PATENT DOCUMENT

Publication Number: US-9939322-B2
Application Number: US-201615542425-A
Country: US
Kind Code: B2

Title: Polarization selective, frequency selective, and wide dynamic range detectors, imaging arrays, readout integrated circuits, and sensor systems

Abstract:
This relates to sensor systems, detectors, imagers, and readout integrated circuits (ROICs) configured to selectively detect one or more frequencies or polarizations of light, capable of operating with a wide dynamic range, or any combination thereof. In some examples, the detector can include one or more light absorbers; the patterns and/or properties of a light absorber can be configured based on the desired measurement wavelength range and/or polarization direction. In some examples, the detector can comprise a plurality of at least partially overlapping light absorbers for enhanced dynamic range detection. In some examples, the detector can be capable of electrostatic tuning for one or more flux levels by varying the response time or sensitivity to account for various flux levels. In some examples, the ROIC can be capable of dynamically adjusting at least one of the frame rate integrating capacitance, and power of the illumination source.

Claims:
What is claimed is: 
     
       1. A light detector, comprising:
 a first light absorber configured to:
 select first light from incident light, and 
 absorb the selected first light, 
 wherein the first light absorber includes one or more first features, the one or more first features including at least one of a plurality of first slits, a first mesh, and a first plate absorber, the one or more first features selective to the selected first light; 
 
 a first temperature sensor thermally coupled to the first light absorber; and 
 a second light absorber configured to:
 select second light from the incident light, and 
 absorb the selected second light, 
 wherein the second light absorber includes one or more second features, the one or more second features including at least one of a plurality of second slits, a second mesh, and a second plate absorber, the one or more second features selective to the selected second light. 
 
 
     
     
       2. The light detector of  claim 1 , wherein the first light absorber includes the plurality of first slits oriented in a first polarizing direction, and the second light absorber includes the plurality of second slits oriented in a second polarizing direction, different from the first polarizing direction. 
     
     
       3. The light detector of  claim 2 , wherein the second polarizing direction is orthogonal to the first polarizing direction. 
     
     
       4. The light detector of  claim 2 , further comprising:
 a third light absorber configured to:
 select third light from the incident light, and 
 absorb the selected third light, 
 wherein the third light absorber includes a plurality of third slits oriented in a third polarizing direction, orthogonal to the first polarizing direction; 
 
 a third temperature sensor thermally coupled to the third light absorber; 
 a fourth light absorber configured to:
 select fourth light from the incident light, and 
 absorb the selected fourth light, 
 wherein the fourth light absorber includes a plurality of fourth slits oriented in a fourth polarizing direction, orthogonal to the second polarizing direction; and 
 
 a fourth temperature sensor thermally coupled to the fourth light absorber. 
 
     
     
       5. The light detector of  claim 1 , further comprising:
 a second temperature sensor thermally coupled to the second light absorber, 
 wherein the first and second temperature sensors are electrically coupled, and the light detector is capable of determining an angle of polarization of light absorbed by the first and second light absorbers based on a differential reading between the first and second temperature sensors. 
 
     
     
       6. The light detector of  claim 1 , wherein the first light absorber includes a plurality of embedded slits or polarizer lines. 
     
     
       7. The light detector of  claim 1 , wherein the plurality of first slits of the first light absorber are spaced a first distance apart, the first distance equal to a quarter of a wavelength of the selected first light. 
     
     
       8. The light detector of  claim 1 , wherein a length of an outer edge of the first light absorber is equal to a long-end wavelength of the selected first light. 
     
     
       9. The light detector of  claim 1 , wherein a distance between adjacent slits included in the plurality of first slits of the first light absorber is equal to a short-end wavelength of the selected first light. 
     
     
       10. The light detector of  claim 1 , the detector further comprising:
 a third light absorber configured to:
 select third light from the incident light, and 
 absorb the selected third light; and 
 
 a fourth light absorber configured to:
 select fourth light from the incident light, and 
 absorb the selected fourth light, 
 
 wherein each light absorber includes a post to thermally couple to the first temperature sensor. 
 
     
     
       11. The light detector of  claim 1 , further comprising:
 an encapsulation disposed on at least a portion of the first light absorber and including a transparent material. 
 
     
     
       12. The light detector of  claim 1 , further comprising:
 an encapsulation supporting at least the first and second light absorbers. 
 
     
     
       13. The light detector of  claim 1 , further comprising:
 a second temperature sensor thermally coupled to the second light absorber; and 
 a processor configured to calculate an angle of polarization of light absorbed by the first and second light absorbers based on at least information from the first and second temperature sensors. 
 
     
     
       14. The light detector of  claim 1 , further comprising:
 a reflector having a surface facing at least one of the first and second light absorbers and spaced a distance equal to a quarter of a wavelength of the selected first light or a wavelength of the selected second light. 
 
     
     
       15. The light detector of  claim 14 , further comprising:
 a second temperature sensor thermally coupled to the second light absorber, 
 wherein the reflector is thermally coupled to at least one of the first and second temperature sensors. 
 
     
     
       16. The light detector of  claim 14 , further comprising:
 one or more structures configured to support the reflector; and 
 an encapsulation, the encapsulation comprising a same material as the one or more structures. 
 
     
     
       17. The light detector of  claim 1 , further comprising:
 a first electrical insulator thermally coupled to the first light absorber and the first temperature sensor, 
 wherein the first electrical insulator electrically isolates the first light absorber from the second light absorber, and 
 further wherein the first temperature sensor thermally couples the first light absorber to the second light absorber. 
 
     
     
       18. The light detector of  claim 1 , wherein the first and second light absorbers are included in a plurality of light absorbers, each light absorber is a mesh, and the plurality of light absorbers form a capacitive resonant mesh. 
     
     
       19. A method of detecting incident radiation, the method comprising:
 applying a first voltage to a first light absorber included in a detector; 
 applying a second voltage to a second light absorber included in the detector; 
 selectively absorbing first light from the incident radiation using the first light absorber, the selective absorption of the first light based on one or more features of the first light absorber, the one or more features including at least one of a plurality of first slits, a first mesh, and a first plate absorber; 
 selectively absorbing second light from the incident radiation using the second light absorber, the selective absorption of the second light based on one or more second features of the second light absorber, the one or more second features including at least one of a plurality of second slits, a second mesh, and a second plate absorber; 
 measuring a first photocurrent from the first light absorber, the first photocurrent indicative of the selectively absorbed first light; 
 measuring a second photocurrent from the second light absorber, the second photocurrent indicative of the selectively absorbed second light; and 
 determining a polarization of the incident radiation based on the measured first and second photocurrents. 
 
     
     
       20. The method of  claim 19 , wherein the second photocurrent is included in the first photocurrent, and further wherein the measurement of the first photocurrent and the measurement of the second photocurrent includes determining a differential reading between the first light absorber and the second light photocurrents.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is a National Phase Patent Application under 35 U.S.C. § 371 of International Application No. PCT/US2016/012753, filed Jan. 8, 2016, which claims the benefit of U.S. Provisional Patent Application No. 62/101,565 filed on Jan. 9, 2015; U.S. Provisional Patent Application No. 62/101,713 filed on Jan. 9, 2015; U.S. Provisional Patent Application No. 62/101,894 filed on Jan. 9, 2015; U.S. Provisional Patent Application No. 62/102,523 filed on Jan. 12, 2015; and U.S. Patent Application No. 62/213,019 filed on Sept. 1, 2015, the entire disclosures of which are herein incorporated by reference for all purposes. 
    
    
     FIELD 
     This relates generally to sensor systems, detectors, imagers, and readout integrated circuits. 
     BACKGROUND 
     Detectors, imaging arrays, readout integrated circuits, and sensor systems can be used for a number of applications, such as imaging or the like. In some examples, detectors and sensor systems capable of selectively detecting light based on frequency and/or polarization can be desired. 
     For a given dynamic range, gain, or mode of operation for a detector, a read-out integrated circuit (ROIC), or both, the sensor system&#39;s performance can be compromised when operating outside normal operating parameters. For example, the dynamic range can be limited by how fast the data or stored charge can be read by the processor, which can be important especially when imaging moving objects, such as a human. Therefore, a detector and ROIC capable of operating with a wide or ultra-wide dynamic range and capable of adjusting the dynamic range, gain, or mode of operation can be desired. 
     An imaging array can be employed to image a scene, and a readout circuit (ROIC) can be coupled to the imaging array to measure the output current from detector pixels included in the imaging array. For a given ROIC, the integrating capacitors can be set prior to operation of the sensor system. However, in some examples, bright (e.g., high photon flux) objects of interest or high illumination powers can lead to high photocurrents measured by the integrating capacitors. Dark current can also be measured by the integrating capacitors, which along with high photocurrents, can lead to saturation of the integrating capacitors. While the system can be cooled or the frame rate can be increased to prevent saturation, these options may be not be suitable for certain applications. The output current from or the optical flux range detected by the detector pixels may change depending on several factors, such as a change in the imaged scene. As a result, the pre-determined parameters of the sensor system may only be optimal for a few instances in time. Therefore, a sensor system and ROIC capable of dynamically adjusting the integrating capacitance, frame rate, illumination source power, and time constant can be desired. 
     SUMMARY 
     This relates to detector and sensor systems. Examples of the disclosure are directed to light detectors configured to selectively detect one or more frequencies or wavelengths within a desired measurement wavelength range. In some examples, the light detector can include one or more light absorbers. The one or more light absorbers can be patterned with a plurality of slits, a mesh, as a plate absorber, or a combination thereof. The dimensions of the light absorber and/or properties of the patterns included in the light absorber can be configured based on the desired measurement wavelength range. Examples of the disclosure are also directed to light detectors configured to detect incident light and determining the polarization of incident light. In some examples, the patterns of the light absorbers can be based on polarization direction. In some examples, the orientation direction of the patterns can be different and such that the detector absorbs a plurality of polarizations. The polarization of the incident light can be determined based on the plurality of light absorbers. 
     This also relates to sensor systems that can include one or more detectors capable of operating with a wide or ultra-wide dynamic range. In some examples, the detector can comprise a plurality of light absorbers with at a least a portion of a first light absorber overlapping a portion of a second light absorber. High flux light can be detected without saturation of the sensor system by allowing the second light absorber to absorb some or all of light not absorbed by the first light absorber. In some examples, low flux light can be accurately detected by allowing incident light to be absorbed by a second light absorber, which can have a lower sensitivity and faster time constant than the first light absorber. In some examples, the detector can comprise a plurality of light absorbers that are non-overlapping. High flux light can be detected by distributing incident light among the plurality of light absorbers, and therefore, saturation of any one light absorber can be prevented. In some examples, at least two of the plurality of light absorbers can have different properties (e.g., dimensions, form factor, heat capacity, and type of material), and therefore, the light absorbers can absorb different amounts of incident light. In some examples, the detector can be capable of electrostatic tuning for one or more flux levels. The electrostatic tuning can vary the response time or sensitivity of the detector to account for both high and low flux light. In some examples, the detector can include an array of detector pixels with intermixed time constants. 
     This also relates to a system and methods for uncooled detection in the shortwave infrared regime. The system can include a detector operating at a high frame rate (e.g., 1-10 kHz) that employs a large integrating capacitor (e.g., 10-200 mega electron) and an illumination source that actively illuminates the active area of the detector pixels. In some examples, at least one of the frame rate, capacitance of the integrating capacitors, and power of the illumination source can be dynamically adjusted to prevent saturation of the integrating capacitors or to achieve a certain image contrast. In some examples, the product of the frame rate and the capacitance of the integrating capacitors can be proportional to the active area of the detector pixels. In some examples, the power of the illumination source can be such that the photocurrent is between 2-10 times greater than the dark current. In some examples, the imaging array can include intermixed time constants, wherein a ROIC can be coupled to the imaging array and operated at multiple frame rates. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  illustrates an exemplary detector pixel in a detector according to examples of the disclosure. 
         FIGS. 2A-2C  illustrate top, plan, and cross-sectional views of an exemplary polarization selective light detector according to examples of the disclosure. 
         FIG. 2D  illustrates an exemplary focal plane array or imager comprising an array of light sensing detector pixels according to examples of the disclosure. 
         FIGS. 3A-3C  illustrate top, plan, and cross-sectional views of an exemplary detector including a plurality of light absorbers located on different layers according to examples of the disclosure. 
         FIGS. 3D-3F  illustrate top, plan, and cross-sectional views of an exemplary detector including a plurality of light absorbers located on different layers and capable of determining an angle of polarization of incident light using a differential reading according to examples of the disclosure. 
         FIG. 3G  illustrates a plan view of an exemplary focal plane array (FPA) or imager comprising an array of light sensing detector pixels according to examples of the disclosure. 
         FIGS. 4A-4C  illustrate top, plan, and cross-section views of an exemplary frequency selective light detector capable of detecting light in one or more selected bands of wavelengths according to examples of the disclosure. 
         FIGS. 4D-4F  illustrate top, plan, and cross-sectional views of an exemplary light detector including a reflector located between the light absorber and the sensor according to examples of the disclosure. 
         FIGS. 4G-4I  illustrate top, plan, and cross-sectional views of an exemplary light detector including a reflector and multiple light absorbers according to examples of the disclosure. 
         FIG. 4J  illustrates a plan view of an exemplary FPA or imager comprising an array of light sensing detector pixels according to examples of the disclosure. 
         FIG. 4K-4M  illustrate cross-sectional views of exemplary light detectors including encapsulated light absorbers according to examples of the disclosure. 
         FIGS. 4N-4O  illustrate top views of exemplary light absorbers including encapsulation according to examples of the disclosure. 
         FIG. 5  illustrates an exemplary ROIC according to examples of the disclosure. 
         FIGS. 6A-6C  illustrate top and cross-sectional views of an exemplary detector pixel including multiple absorbers according to examples of the disclosure. 
         FIGS. 7A-7B  illustrate exemplary top and cross-sectional views of a detector pixel including multiple absorbers according to examples of the disclosure. 
         FIGS. 8A-8B  illustrate exemplary top and cross-sectional views of a detector pixel including multiple absorbers with different sizes according to examples of the disclosure. 
         FIG. 9A  illustrates a plan view of a portion of an exemplary detector capable of electrostatically tuning according to examples of the disclosure. 
         FIG. 9B  illustrates a plan view of a portion of an exemplary detector illustrating a substrate configured as an electrostatic capacitor plate according to examples of the disclosure. 
         FIGS. 9C-9E  illustrate top, plan, and cross-sectional views of an exemplary detector capable of electrostatically tuning for one or more flux levels according to examples of the disclosure. 
         FIG. 10  illustrates plan view of a portion of an exemplary detector illustrating a plurality of detector pixels with intermixed time constants according to examples of the disclosure. 
         FIG. 11A  illustrates an exemplary ROIC capable of multiple frame rates according to examples of the disclosure. 
         FIG. 11B  illustrates an exemplary ROIC capable of multiple frame rates with unit cells arranged in a checkboard-pattern according to examples of the disclosure. 
         FIG. 12  illustrates an exemplary process flow for adjusting one or more parameters of the ROIC to prevent saturation of the integrated capacitors according to examples of the disclosure. 
     
    
    
     DETAILED DESCRIPTION 
     In the following description of examples, reference is made to the accompanying drawings in which it is shown by way of illustration specific examples that can be practiced. It is to be understood that other examples can be used and structural changes can be made without departing from the scope of the various examples. 
     Representative applications of methods and apparatus according to the present disclosure are described in this section. These examples are being provided solely to add context and aid in the understanding of the described examples. It will thus be apparent to one skilled in the art that the described examples may be practiced without some or all of the specific details. Other applications are possible, such that the following examples should not be taken as limiting. 
     Various techniques and process flow steps will be described in detail with reference to examples as illustrated in the accompanying drawings. In the following description, numerous specific details are set forth in order to provide a thorough understanding of one or more aspects and/or features described or referenced herein. It will be apparent, however, to one skilled in the art, that one or more aspects and/or features described or referenced herein may be practiced without some or all of these specific details. In other instances, well-known process steps and/or structures have not been described in detail in order to not obscure some of the aspects and/or features described or referenced herein. 
     Further, although process steps or method steps can be described in a sequential order, such processes and methods can be configured to work in any suitable order. In other words, any sequence or order of steps that can be described in the disclosure does not, in and of itself, indicate a requirement that the steps be performed in that order. Further, some steps may be performed simultaneously despite being described or implied as occurring non-simultaneously (e.g., because one step is described after the other step). Moreover, the illustration of a process by its depiction in a drawing does not imply that the illustrated process is exclusive of other variations and modification thereto, does not imply that the illustrated process or any of its steps are necessary to one or more of the examples, and does not imply that the illustrated process is preferred. 
     In some examples, a detector capable of operating at or near room temperature may be desired. Detectors operating in the short-wave infrared (SWIR) range can include Mercury Cadmium Telluride (HgCdTe) based, Indium Antimonide (InSb) based, and Indium Gallium Arsenide (InGaAs) based detectors. However, in some examples, these types of detectors can have performance characteristics insufficient for characterization of an object. Additionally, these types of detectors can require cryogenic cooling, which may not be suitable for portable electronic devices, whose size and weight requirements can be limited. 
     One type of detector capable operating at or near room temperature can be bolometers or microbolometers.  FIG. 1  illustrates an exemplary detector pixel according to examples of the disclosure. In some examples, detector pixel  100  can be a bolometer. A detector pixel can include one or more detector elements with a common footprint. A detector element can be an element designed to detect the presence of light and can individually generate a signal representative of the detected light. A bolometer can be a type of thermal detector that operates by detecting changes in temperature or resistance of a material. Detector pixel  100  can include a light absorber  110 . Light absorber  110  can be any type of material capable of absorbing light. Light absorber  110  can be exposed to electromagnetic radiation or light, and any light absorbed by light absorber  110  can produce heat within the light absorber, changing its temperature. The change in temperature can be proportional to the amount of light absorbed. Light absorber  110  can be thermally coupled to a sensor  120  mounted on a substrate  170 . The change in temperature in the light absorber can cause a change in the resistance of sensor  120 . Sensor  120  can be electrically coupled to an integrated circuit (not shown) through contact  130 . The integrated circuit can be coupled to a processor, computer, or controller, which can bias detector pixel  100  with a constant current or constant voltage and can measure the change in resistance due to light impinging on the surface of light absorber  110 . 
     Light incident on an object can penetrate to one or more depths within the object. When light is incident on the object, a portion of incident light can reflect off the object&#39;s surface. Another portion of the light incident on the object can enter superficially, but can reflect back. In some examples, it may be desirable to distinguish between portions of reflected light (e.g., light that reflects off the object&#39;s surface and light that only enters the object superficially) from light that reaches deeper portions in the object. If the detector is unable to distinguish between light that has reflected at the object&#39;s surface or has only entered superficially and light that has entered deeper into the object, the processor may make an erroneous measurement of the object&#39;s properties. 
     The accuracy of the measured transmittance, refractive index, reflectance, absorbance, or material composition can be improved by measuring light of certain polarizations or by determining the characteristics of polarized light. Scattering events within an object can depolarize light, and the probability of a scattering event can increase with the depth of light penetration in the object. Light that enters into deeper into the object can be randomized, and photons reflecting back towards the detector can be depolarized. Conversely, polarized light that specularly reflects off the object&#39;s surface can maintain its polarization. Similarly, light that only enters the object superficially can maintain a large degree of its polarization. Therefore, a detector capable of polarization selectivity can be desired. 
       FIGS. 2A-2C  illustrate top, plan, and cross-sectional views of an exemplary polarization selective light detector according to examples of the disclosure. Detector pixel  200  can include a plurality of detector elements, such as detector element  201 , detector element  203 , detector element  205 , and detector element  207 . Detector element  201  can include a first light absorber  210 . First light absorber  210  can include any material capable of absorbing light. Exemplary materials for light absorbers can include, but are not limited to, Nickel Chrome (NiCr), Phosphor Bronze, Vanadium Oxide (V x O y ), and amorphous Silicon (a-Si). In some examples, first light absorber  210  can have a large temperature coefficient of resistance (TCR). The TCR can be a measure of the change in resistance in response to a change in temperature. Therefore, a light absorber with a large TCR can detect small or minute changes in temperature induced by the incident radiation. For example, light impinging on first light absorber  210  can cause an increase in the temperature of the first light absorber  210 . First light absorber  210  can include V x O y , where a small increase in temperature can lead to a large decrease in the resistance. Detector element  201  can include a first sensor  220  mounted on substrate  270 . First sensor  220  can be a temperature sensor or any type of sensor capable of measuring a change in temperature, such as a thermistor. In some examples, first sensor  220  can be a resistor capable of changing a resistance in relation to changes in temperature experienced by first light absorber  210 . 
     First light absorber  210  can be coupled to a first post  240 . First post  240  can include any type of material capable of conducting heat from first light absorber  210  to first sensor  220 . Any change in temperature of first light absorber  210  due to the absorbed incident light can be experienced and detected by first sensor  220 . In some examples, first light absorber  210  can be coupled to one post. In some examples, first light absorber  210  can be coupled to multiple posts. In some examples, first sensor  220  can be thermally coupled to first light absorber  210  by a direct or indirect physical connection through which heat can conduct. For example, first light absorber  210  can be directly coupled to first sensor  220 , or heat may conduct through one or more intervening structures located between first light absorber  210  and first sensor  220  that are directly physically coupled to first light absorber  210  and first sensor  220 . In some examples, the indirect physical connection can be a material used to alter the thermal conduction between first light absorber  210  and first sensor  220 . 
     Substrate  270  can include contact  230  and contact  231 . Contact  230  and contact  231  can be coupled to an integrated circuit, such as a read-out integrated circuit (ROIC). The integrated circuit can be coupled to a processor or controller. In some examples, the processor can bias the detector with a constant current or constant voltage and can measure the change in resistance due to light impinging on the light absorber. Since an integrated circuit can be coupled to first sensor  220  through contact  230  and contact  231 , the integrated circuit can transmit the information to a processor (or controller) for determining the properties of incident light. 
     First light absorber  210  can comprise a plurality of slits  250  oriented in first polarizing direction  260 . The configuration of plurality of slits  250  can be such that detector element  201  can be configured to selectively absorb a specific polarization of light, while allowing other polarizations of light to transmit through. The orientation of plurality of slits  250  in first polarizing direction  260  can allow first light absorber  210  to absorb light with first polarizing direction  260 . Although not as strongly absorbed as light polarized in the same direction as first polarizing direction  260 , light polarized in other polarizing directions (e.g., second polarizing direction  262  and fourth polarizing direction  266 ) can still be absorbed. For example, first light absorber  210  can absorb greater than 90% of light polarized in the same direction as first polarizing direction  260 , while absorbing about 50% of light oriented 45° relative to first polarizing direction  260  (e.g., light with second polarizing direction  262 ) and absorbing 0% of light oriented orthogonally relative to first polarizing direction  260  (e.g., third polarizing direction  264 ). Therefore, first light absorber  210  can absorb different polarizations of light, and as a result, may not be able to differentiate between a change in the magnitude of incident light and a change in the angle of polarization of incident light. 
     Detector element  203  can include a second light absorber  212 . Second light absorber  212  can be coupled to a second post  242 . Second post  242  can include any type of material capable of conducting heat from second light absorber  212  to second sensor  222 . In some examples, second light absorber  212  can be coupled to one post. In some examples, second light absorber  212  can be coupled to multiple posts. In some examples, second sensor  222  can be thermally coupled to second light absorber  212  by a direct or indirect physical connection through which heat can conduct. For example, second light absorber  212  can be directly coupled to second sensor  222 , or heat may conduct through one or more intervening structures located between second light absorber  212  and second sensor  222  that are directly physically coupled to second light absorber  212  and second sensor  222 . Substrate  270  can include contact  232  and contact  233 . Contact  232  and contact  233  can be coupled to an integrated circuit, such as a ROIC, and information about the change in temperature or change in resistance measured by second sensor  222  can be transmitted to the processor through the contact  232 , contact  233 , and ROIC. 
     By utilizing a plurality of light absorbers, the processor can differentiate between a change in the magnitude of incident light and a change in the angle of polarization of incident light. Second light absorber  212  can comprise a plurality of slits  252  oriented in second polarizing direction  262 . In some examples, the polarizing direction (e.g., second polarizing direction  262 ) of one light absorber can be different from the polarizing direction (e.g., first polarizing direction  260 ) of another light absorber. For example, second polarizing direction  262  can be oriented 45° relative to first polarizing direction  260 . Similar to first light absorber  210 , second light absorber  212  can absorb light polarized in a plurality of directions, where light polarized in the same direction as polarizing direction can be absorbed more strongly. Generally, the amount of light absorbed by a light absorber can be proportional to the difference between the orientation of the polarized light and the direction of the plurality of slits. 
     Therefore, the larger difference between the orientation of the polarized light and the direction of the plurality of slits, the lower the amount of light absorbed. 
     Using the information extracted from the plurality of slits, the processor can determine an angle of polarization of incident light. Any unpolarized light can be absorbed equally by each light absorber, and thus, any variation due to the absorption of unpolarized light can be canceled out based on information from the detected polarized light. The angle of polarization of light can be determined by: 
                     θ   L     =           x   A     ⁡     (       90   ∘     -     θ   B       )       -       x   B     ⁡     (       90   ∘     -     θ   A       )             -     x   A       -     x   B                 (   1   )               
where x A  is the absorption from first light absorber  210 , x B  is the absorption from second light absorber  212 , θ A  is the polarizing direction of first light absorber  210  (e.g., first polarization direction  260 ), and θ B  is the polarizing direction of second light absorber  212  (e.g., second polarization direction  262 ).
 
     Detector element  205  can include third light absorber  214 , coupled to third sensor  224 , and fourth light absorber  216 , coupled to fourth sensor  226 . Each of light absorbers  210 ,  212 ,  214 , and  216  can include a plurality of slits oriented in different polarizing directions. For example, second polarizing direction  262  can be 45° degrees relative to first polarizing direction  260 . Third light absorber  214  can include a plurality of slits  254  oriented in a third polarizing direction  264 , where third polarizing direction  264  can be orthogonal or close to orthogonal to first polarizing direction  260  (e.g., the third polarizing direction can be oriented 90°±5° relative to first polarizing direction  260 ). Fourth light absorber  216  can include a plurality of slits  256  oriented in a fourth polarizing direction  266 , where fourth polarizing direction  266  can be oriented 90°±5° relative to second polarizing direction  262 . A processor can calculate an angle of polarization of light absorbed by first light absorber  210 , second light absorber  212 , third light absorber  214 , and fourth light absorber  216  based on information (e.g., light absorption values) obtained from the plurality of sensors (e.g., first sensor  220 , second sensor  222 , third sensor  224 , and fourth sensor  226 ). 
       FIGS. 2A-2B  illustrate an exemplary configuration of first light absorber  210  and second light absorber  212  located in a first row, third light absorber  214  and fourth light absorber  216  located in a second row, first light absorber  210  and third light absorber  214  located in a first column, and second light absorber  212  and fourth light absorber  216  located in a second column of detector pixel  200 . In some examples, detector pixel  200  can include first light absorber  210  and second light absorber  212 , but may not include third light absorber  214 , fourth light absorber  216 , nor the corresponding third sensor  224  and fourth sensor  226 . For example, detector pixel  200  can include first light absorber  210  and second light absorber  212 , where second polarizing direction  262  of second light absorber  212  can be orthogonal to first polarizing direction  260  of first light absorber  210  (e.g., second polarizing direction  262  can be oriented 90°±5° relative to first polarizing direction  260 ). 
     In some examples, the plurality of slits in the light absorber and/or the dimensions of the light absorber can be configured based on the wavelength or range of wavelengths of interest. For example, the spacing of the slits in the light absorber and the dimensions of the light absorber itself can be adjusted to absorb light with one or more specific wavelengths. Absorbed light can reach maximum amplitude when its distance from the point of reflection (e.g., surface of the light absorber) is equal to a quarter of the wavelength of the light (or a multiple of the quarter of the wavelength of light). Accordingly, a light absorber having a given length can absorb more strongly any light having a wavelength equal to four times the length of outer edge of the light absorber. Conversely, light having a given wavelength can be more strongly absorbed by a light absorber when having a length equal to a quarter of the given wavelength. To benefit from the maximum amplitude, the light absorber can be configured with a length that is four times the wavelength of light, thereby enhancing the amount of absorption by the light absorber. 
     The light absorber can be configured to absorb a range of wavelengths defined by a low or short-end wavelength and a high or long-end wavelength. For example, the length (e.g., 10-17 μm for a wavelength of 2.5-4.25 μm) of the outer edge of a light absorber (e.g., the length of the longest edge of an absorbing surface of the light absorber) can define the long-end wavelength (of the range) of light to be absorbed by the light absorber, and the distance (e.g., 0.65 μm) between adjacent slits in the light absorber can define the short-end wavelength (of the range). For example, the light absorber may not strongly absorb light having a wavelength that is longer than four times the length of its outer edge. In addition, for example, the light absorber may not strongly absorb light having a wavelength that is shorter than four times the distance between adjacent slits in the light absorber. In some examples, the light absorber can be configured to absorb at least a specific wavelength of light (e.g., light in the infrared spectrum), and the plurality of slits in a light absorber can be spaced apart a first distance equal to a quarter of the specific wavelength of light. In some examples, the plurality of slits of each of the four light absorbers can be spaced the same distance. One skilled in the art would appreciate that the same distance can include tolerances that result in a 15% deviation. 
     The post, such as first post  240  coupled to first light absorber  210 , can be located at a corner of the light absorber, and the light absorber can be thermally coupled to the sensor, such as first sensor  220 , through the post. As illustrated in  FIGS. 2A-2C , this configuration can offset each light absorber from its corresponding sensor. Examples of the disclosure can include other configurations. For example, the post can be located at the center of each light absorber, instead of at the corner of each light absorber, or the post can include an offset from the center of each light absorber while not being located at the corner. In some examples, each post can be located at the same corner (e.g., upper-left) of the corresponding light absorber, as illustrated in  FIGS. 2A-2B . In other examples, each post can be located at a different corner of a corresponding light absorber (e.g., the posts can be located at different corners of the light absorbers), and the posts can be grouped together such that the light absorbers fan out from the center of the detector, like petals in a four-petal configuration. 
       FIG. 2D  illustrates an exemplary focal plane array or imager comprising an array of light sensing detector pixels according to examples of the disclosure. Detector pixel  200  can be included in a focal plane array (FPA) or imager  290 . An FPA can be an image-sensing device comprising an array of optical sensors. In some examples, imager  290  can be an infrared imager. In some examples, the other detector pixels in the array of detector pixels or imager  290  can be configured with four light absorbers in each detector pixel. Imager  290  can include a plurality of detector pixels coupled to an integrated circuit, such as a ROIC. Each detector pixel can be biased individually or can be coupled to the same biasing circuitry. Each detector pixel can be coupled to a different circuit on the ROIC. Each circuit on the ROIC can store charge corresponding to the detected light (or photons of light) on the corresponding detector pixel in an integrating capacitor to be sampled and read out by the processor to generate an image. In some examples, one contact for the plurality of detector pixels can be coupled to a common electrode, such as Vdetcom (not shown), while the other contact can be coupled to different electrode or voltage source. Although the figure illustrates four light absorbers, examples of the disclosure can include any number of light absorbers. Additionally, although four detector pixels in a 2×2 row-column arrangement are illustrated in the figure, examples of the disclosure can include any number of detector pixels and can be configured in any arrangement. Although  FIG. 2D  illustrates arrays of the same or repeated configuration of detector pixels, examples of the disclosure are not limited to detectors comprising arrays of the same or repeated configuration of detector pixels. In some examples, an array can include any combination of light detectors described herein, including any and/or all of the detectors illustrated in and described with respect to the other figures. 
       FIGS. 3A-3C  illustrate top, plan, and cross-sectional views of an exemplary detector including a plurality of light absorbers located on different layers according to examples of the disclosure. Detector pixel  300  can include a first light absorber  310  and a second light absorber  312 . First light absorber  310  and second light absorber  312  can be any material capable of absorbing light, including, but not limited to, NiCr, Phosphor Bronze, V x O y , and a-Si. In some examples, first light absorber  310  and second light absorber  312  can be include materials of the same composition. One skilled in the art would appreciate that the same material composition can include tolerances that result in a 15% deviation. In some examples, first light absorber  310  can be located closer to incident light than second light absorber  312 . In some examples, second light absorber  312  can be located closer to substrate  370  than first light absorber  310 . In some examples, first light absorber  310 , second light absorber  312 , or both can have a large TCR and can be capable of detecting small or minute changes in temperature (e.g., a large resistance change per change in material temperature). 
     First light absorber  310  can include a plurality of slits  350  oriented in first polarizing direction  360 . First light absorber  310  can be thermally coupled to a first sensor  320  through first post  340 . First sensor  320  can be any type of sensor capable of measuring a change in temperature, such as a thermistor. In some examples, first sensor  320  can be a resistor capable of changing a resistance in relation to changes in temperature experienced by first light absorber  310 . 
     First post  340  can include any type of material capable of conducting heat from first light absorber  310  to first sensor  320 . In some examples, first light absorber  310  can be coupled to one post. In some examples, first light absorber  310  can be coupled to multiple posts. In some examples, first sensor  320  can be thermally coupled to first light absorber  310  by a direct or indirect physical connection through which heat can conduct. For example, first light absorber  310  can be directly coupled to first sensor  320 , or heat may conduct through one or more intervening structures located between first light absorber  310  and first sensor  320  that are directly coupled to first light absorber  310  and first sensor  320 . 
     Substrate  370  can include contact  330  and contact  331  coupled to first light absorber  310 , first sensor  320 , and first post  340 . Contact  330  and contact  331  can also be coupled to an integrated circuit, such as a ROIC. The integrated circuit can be coupled to a processor or controller. In some examples, the processor can bias the detector with a constant current or constant voltage and can measure the change in resistance due to light impinging on the light absorber. 
     Second light absorber  312  can include a plurality of slits  352  oriented in second polarizing direction  362 . In some examples, second polarizing direction  362  can be different from first polarizing direction  360 . For example, second polarizing direction  362  can be oriented 90°±5° or 45°±5° relative to first polarizing direction  360 . 
     Second light absorber  312  can be thermally coupled to a second sensor  322  through second post  342 . Second sensor  322  can be mounted on substrate  370  and can be any type of sensor capable of measuring a change in temperature, such as a thermistor. In some examples, second sensor  322  can be a resistor capable of changing a resistance in relation to changes in temperature experienced by second light absorber  312 . 
     Second light absorber  312  can be thermally coupled to second post  342 . Second post  342  can include any type of material capable of conducting heat from second light absorber  312  to second sensor  322 . In some examples, second light absorber  312  can include one post. In some examples, second light absorber  312  can include multiple posts. In some examples, second sensor  322  can be thermally coupled to second light absorber  312  by a direct or indirect physical connection through which heat can conduct. For example, second light absorber  312  can be directly coupled to second sensor  322 , or heat may conduct through one or more intervening structures located between second sensor  322  and second light absorber  312  that are directly coupled to second sensor  322  and second light absorber  312 . In some examples, first post  340  and second post  342  can have the same electrical properties. One skilled in the art would appreciate that the same electrical properties can include tolerances that result in a 15% deviation. 
     Substrate  370  can include contact  332  and contact  333  coupled to second light absorber  312 , second sensor  322 , and second post  342 . Contact  332  and contact  333  can be coupled to an integrated circuit, such as a ROIC. The integrated circuit can be coupled to a processor or controller, which can bias the detector with a constant current or constant voltage and can measure the change in resistance due to light impinging on the light absorber. In some examples, the processor can bias the detector with a constant current or constant voltage and can measure the change in resistance due to light impinging on the light absorber. In some examples, at least one contact (e.g., contact  330  or contact  331 ) coupled to first light absorber  310  and at least one contact (e.g., contact  332  or contact  333 ) coupled to second light absorber  312  can be coupled to a common voltage, such as Vdetcom. In some examples, contact  330  or contact  331  and contact  332  or contact  333  can be coupled to the same biasing voltage source. In some examples, contact  330  or contact  331  and contact  332  or contact  333  can be coupled to the same circuitry on the integrated circuit (e.g., ROIC). 
     Plurality of slits  350  of first light absorber  310  can overlap plurality of slits  352  of second light absorber  312 , as illustrated in  FIGS. 3A-3B , such that first light absorber  310  and second light absorber  312  can be co-located in a configuration with visually overlapping slits. For example, plurality of slits  350  of first light absorber  310  can visually overlap plurality of slits  352  of second light absorber  312  such that light transmitting through plurality of slits  350  of first light absorber  310  may be absorbed by second light absorber  312 . Further, an angle of polarization of light absorbed can be calculated based on light absorption values obtained from first light absorber  310  and second light absorber  312 , similar to the example described above with reference to  FIGS. 2A-2C . As illustrated in  FIGS. 3A-3C , first light absorber  310  and second light absorber  312  can have the same dimensions and can be aligned such that the footprint of the detector pixel on substrate  370  is no larger than the footprint of a light absorber. One skilled in the art would appreciate that the same dimensions can include tolerances that result in a 15% deviation. 
     In some examples, first light absorber  310  and second light absorber  312  can absorb light in a range of wavelengths, where the range of wavelengths can be determined by the spacing of the slits in each respective light absorber and the dimensions of each respective light absorber. As discussed above, a light absorber with a given length can more strongly absorb light with a wavelength that is four times that given length, and light having a given wavelength can be absorbed most strongly by a light absorber having a length equal to (or within 10% from) a quarter of the given wavelength. 
     First light absorber  310 , second light absorber  312 , or both can be configured to absorb a range of wavelengths defined by a low or short-end wavelength and a high or long-end wavelength. For example, the length (e.g., 10-17 μm) of the outer edge of the light absorber (e.g., the length of the longest edge of an absorbing surface of the light absorber) can define the long-end wavelength (of the range) of light to be absorbed by the light absorber (e.g., the light absorber may not strongly absorb light having a wavelength that is longer than four times the length of its outer edge), and the distance (e.g., 0.65 μm) between adjacent slits in the light absorber can define the short-end wavelength (of the range) (e.g., the light absorber may not strongly absorb light having a wavelength that is shorter than four times the distance between adjacent slits in the light absorber). In some examples, first light absorber  310  and second light absorber  312  can be configured to absorb at least a first wavelength of light (e.g., light in the infrared spectrum), and plurality of slits  350  oriented in first polarization direction  360  can be spaced apart a first distance equal to (or within 10% from) a quarter of the wavelength of light. In some examples, plurality of slits  352  oriented in second polarizing direction  362  in second light absorber  312  can be spaced apart a quarter of the wavelength of light. 
     In some examples, first light absorber  310  can be spaced a distance from second light absorber  312 , and the distance can be, for example, a quarter of the wavelength of light to be absorbed by first light absorber  310  and second light absorber  312 . The distance between the first and second light absorbers being a quarter of a wavelength of light can create a resonant cavity effect between first light absorber  310  and second light absorber  312  for light of that wavelength. The resonant cavity effect can increase the efficiency of light absorption for both light absorbers. 
     In some examples, first light absorber  310  can include a first post  340  that transmits through second light absorber  312 , while first light absorber  310  and second light absorber  312  can remain thermally isolated from each other. In some examples, first post  340  can transmit through one or more of plurality of slits  352  in second light absorber  312 . In some examples, first post  340  and second post  342  can be coupled to the same sensor. In some examples, as illustrated in  FIGS. 3A-3C , first post  340  (coupled to first light absorber  310 ) can be at a first position, and second post  342  (coupled to second light absorber  312 ) can be at a second position. The first position and the second position can be symmetric with respect to a center position halfway between first light absorber  310  and second light absorber  312 . In such a configuration, first post  340  and second post  342  can obscure the configuration of the slits symmetrically for both first polarizing direction  360  and second polarizing direction  362 , such that the polarizing sensitivity of detector pixel  300  may not be biased towards one polarizing direction or the other. In some examples, first post  340  and second post  342  can be located at the corners of detector pixel  300 . 
       FIGS. 3D-3F  illustrate top, plan, and cross-sectional views of an exemplary detector including a plurality of light absorbers located on different layers and capable of determining an angle of polarization of incident light using a differential reading according to examples of the disclosure. Detector pixel  300  can include a first light absorber  310  and a second light absorber  312 . First light absorber  310  and second light absorber  312  can be any material capable of absorbing light, including, but not limited to, NiCr, Phosphor Bronze, V x O y , and a-Si. In some examples, first light absorber  310  and second light absorber  312  can be include materials of the same composition. One skilled in the art would appreciate that the same material composition can include tolerances that result in a 15% deviation. In some examples, first light absorber  310  can be located closer to incident light than second light absorber  312 . In some examples, second light absorber  312  can be located closer to substrate  370  than first light absorber  310 . First light absorber  310  can include a plurality of slits  350  oriented in first polarizing direction  360 . First light absorber  310  can be thermally coupled to a first sensor  320  through first post  340 . First sensor  320  can be any type of sensor capable of measuring a change in temperature, such as a thermistor. In some examples, first sensor  320  can be a resistor capable of changing a resistance in relation to changes in temperature experienced by first light absorber  310 . First post  340  can include any type of material capable of conducting heat from first light absorber  310  to first sensor  320 . In some examples, first light absorber  310  can be coupled to one post. In some examples, first light absorber  310  can be coupled to multiple posts. 
     Second light absorber  312  can include a plurality of slits  352  oriented in second polarizing direction  362 . In some examples, second polarizing direction  362  can be different from first polarizing direction  360 . For example, second polarizing direction  362  can be oriented 90°±5° or 45°±5° relative to first polarizing direction  360 . Second light absorber  312  can be thermally coupled to a second sensor  322  through second post  342 . Second post  342  can include any type of material capable of conducting heat from second light absorber  312  to second sensor  322 . In some examples, second light absorber  312  can include one post. In some examples, second light absorber  312  can include multiple posts. In some examples, second sensor  322  can be thermally coupled to second light absorber  312  by a direct or indirect physical connection through which heat can conduct. For example, second light absorber  312  can be directly coupled to second sensor  322 , or heat may conduct through one or more intervening structures between second sensor  322  and second light absorber  312  that are directly coupled to second sensor  322  and second light absorber  312 . 
     First sensor  320  can be coupled to a contact  331 , and second sensor  322  can be coupled to a contact  332 . Detector pixel  300  can include another contact  330  located on substrate  370 . Contact  330  can be coupled to both first sensor  320  and second sensor  322  (i.e., both first sensor  320  and second sensor  322  can be coupled to the same contact  330 ). This configuration can allow an angle of polarization of light absorbed by first light absorber  310  and second light absorber  312  to be determined based on a differential reading between first sensor  320  and second sensor  322 . By determining the angle of polarization based on a differential reading, the processor may no longer be needed to perform the calculation based on light absorption values from each light absorber as described above with respect to  FIGS. 3A-3C . 
       FIG. 3G  illustrates a plan view of an exemplary FPA or imager comprising an array of light sensing detector pixels according to examples of the disclosure. Detector pixel  300  can be included in FPA or imager  390 . An FPA can be an image-sensing device comprising an array of optical sensors. Detector pixel  300  can be incorporated as a first light sensing detector pixel (e.g., an infrared light sensing detector pixel) including a first light absorber and a second light absorber. In some examples, imager  390  can be an infrared imager. In some examples, the imager can comprise an array of detector pixels, where each detector pixel can be configured with a first light absorber and a second light absorber. In some examples, imager  390  can be arranged as two rows and two columns (i.e., a 2×2 arrangement). For example, the first light absorber and second light absorber of detector pixel  300  can be co-located in a first column of a first row, while detector pixel  302  (including first light absorber  310  and second light absorber  312 ) can be co-located in a second column of the first row. The 2×2 arrangement can include a total of eight light absorbers and four detector pixels. In some examples, the light absorbers of detector pixel  300  can have different polarizing directions or orientations than the light absorbers of detector pixel  302 . For example, detector pixel  300  can have a plurality of slits oriented in first polarizing direction  360  that is oriented 45° relative to plurality of slits in detector pixel  302 , which is oriented in second polarizing direction  362 . In some examples, the other detector pixels (e.g., detector pixel  304  and detector pixel  306 ) included in imager  390  can each be oriented with polarizing directions different from each other and/or different from detector pixel  300  and detector pixel  302 . 
     In some examples, a first row of light absorbers (e.g., first, second, third, and fourth light absorbers) can be included in a light sensing detector pixel along with a second row of light absorbers (fifth, sixth, seventh, and eighth light absorbers). The fifth and sixth light absorbers (e.g., fifth light absorber  311  and sixth light absorber  313 ) can be co-located in a first column of the second row of the detector pixel, and the seventh and eighth light absorbers (e.g., seventh light absorber  315  and eighth light absorber  317 ) can be co-located in a second column of the second row of the detector pixel. Each of the light absorbers in the second row can share a polarizing direction with a light absorber from the first row. For example, fifth light absorber  311  included in detector pixel  304  located in the second row can be oriented with the same polarization direction as second light absorber  312  included in detector pixel  302  located in the first row. In some examples, the arrangement of the second row can be different from the arrangement of the first row to account for minute differences that may occur from having one light absorber located above the other. For example, in the first row, a light absorber (e.g., second light absorber  312 ) can have slits oriented in a third polarizing direction  364  and can be located further away from incident light than another light absorber (e.g., first light absorber  310 ), whose slits are oriented in second polarizing direction  362 . On the other hand, in the second row, a light absorber (e.g., fifth light absorber  311 ) having the same third polarizing direction  364  can be closer to incident light than another light absorber (e.g., sixth light absorber  313 ) oriented in the same second polarizing direction  362 . In some examples, sixth light absorber  313  can be located closer to substrate  370  than the fifth light absorber  311 . Similarly, in the first row, a light absorber including slits oriented in first polarizing direction  360  can be located closer to incident light (or further away from substrate  370 ) than another light absorber including slits oriented in a fourth polarizing direction  366 , whereas, in the second row, a light absorber including slits oriented in first polarizing direction  360  can be located further away from incident light (or closer to substrate  370 ) than another light absorber including slits oriented in a fourth polarizing direction  366 . 
     In some examples, the other detector pixels in the array of detector pixels or imager  390  can be configured with two (or more) light absorbers in each detector pixel. The plurality of detector pixels can be coupled to an integrated circuit, such as a ROIC. Each detector pixel can be biased individually or can be coupled to the same biasing circuitry. Each detector pixel can be coupled to a different circuit on the ROIC. Each circuit on the ROIC can store charge corresponding to the detected light (or photons of light) on the corresponding detector pixel in an integrating capacitor to be sampled and read out by the processor to generate an image. In some examples, one contact for the plurality of detector pixels can be coupled to a common electrode, such as Vdetcom (not shown), while the other contact can be coupled to different electrode or voltage source. Although the figures illustrate two light absorbers per detector pixel, examples of the disclosure can include any number of light absorbers per detector pixel. Additionally, although four detector pixels in a 2×2 row-column arrangement are illustrated in the figures, examples of the disclosure can include any number of detector pixels and can be configured in any arrangement. Although  FIG. 3G  illustrates arrays of the same or repeated configuration of detectors or detector pixels, examples of the disclosure are not limited to detectors comprising arrays of the same or repeated configuration of detector pixels. In some examples, an array can include any combination of light detectors described herein, including any and/or all of the detectors illustrated in and described with respect to the other figures. 
       FIGS. 4A-4C  illustrate top, plan, and cross-section views of an exemplary frequency selective light detector capable of detecting light in one or more selected bands of wavelengths according to examples of the disclosure. Detector pixel  400  can include a plurality of detector elements, such as detector element  401 , and a plurality of light absorbers, such as light absorbers  410 . Light absorbers  410  can include any material, such as NiCr, Phosphor Bronze, V x O y , and a-Si, capable of absorbing light. Detector pixel  400  can include a sensor  420  mounted on substrate  470 , where each light absorber  410  can be coupled to sensor  420 . Sensor  420  can be a temperature sensor or any type of sensor capable of measuring a change in temperature, such as a thermistor. In some examples, sensor  420  can be a resistor capable of changing a resistance in relation to changes in temperature experienced by the light absorbers  410 . In some examples, sensor  420  can have a large TCR, and can be capable of detecting small or minute changes in the temperature in light absorbers  410 . 
     Detector pixel  400  can include a plurality of posts  440 , where each light absorber  410  can be coupled to a post  440 . Post  440  can include any type of material capable of conducting heat from the corresponding light absorber  410  to sensor  420 . In some examples, sensor  420  can be thermally coupled to light absorbers  410  by a direct or indirect physical connection through which heat can conduct. For example, light absorbers  410  can be directly coupled to the sensor  420 , or heat may conduct through one or more intervening structures located between light absorbers  410  and sensor  420  that are directly physically coupled to light absorber  410  and sensor  420 . 
     In some examples, one or more of the plurality of posts  440  can include an electrical insulator  441 . Through post  440  and electrical insulator  441 , a light absorber  410  can be thermally coupled (e.g., a physical connection through which heat can conduct) to sensor  420 . For example, as illustrated in  FIGS. 4A-4C , each light absorber  410  can be coupled to an electrical insulator  441 . The electrical insulator  441  can be thermally coupled to sensor  420 , which can allow heat to transmit between the corresponding light absorber  410  and sensor  420 , while electrically isolating light absorbers  410  from sensor  420 . In turn, the electrical insulator  441  can electrically isolate each light absorber  410  from other light absorbers included in the plurality of light absorbers  410 , while the plurality of light absorbers  410  can be thermally coupled to each other through sensor  420 . 
     As illustrated in  FIGS. 4A-4C , each respective light absorber  410  can have a corresponding electrical insulator  441  that thermally couples the respective light absorber to sensor  420 . In some examples, a single electrical insulator, such as electrical insulator  441 , can thermally couple the plurality of light absorbers  410  to sensor  420 , while electrically isolating the plurality of light absorbers  410  from each other. That is, the plurality of light absorbers  410  can share electrical insulator  441 . In some examples, detector pixel  400  can include multiple electrical insulators, one or more of which have multiple light absorbers directly coupled thereto, and each of the multiple electrical insulators can be directly coupled to sensor  420 . 
     Substrate  470  can include contact  430  and contact  431 . Contact  430  and contact  431  can be coupled to an integrated circuit, such as a ROIC. The integrated circuit can be coupled to a processor or controller. In some examples, the processor can bias the detector with a constant current or constant voltage and can measure the change in resistance due to the light impinging on the light absorber. 
     In some examples, each of the plurality of light absorbers  410  can be a mesh, and the plurality of light absorbers  410  can form a capacitive resonant mesh. In some examples, each light absorber  410  can include a grid of wires forming the mesh. For example, as illustrated in  FIGS. 4A-4C , the light absorbers can be coplanar and can form a capacitive resonant mesh such that the plurality of light absorbers  410  only absorb light in a range of wavelengths determined by the spacing of the wires in the metal mesh and the dimensions of light absorbers  410 . 
     The plurality of light absorbers  410  can be configured to absorb a range of wavelengths defined by a low or short-end wavelength and a high or long-end wavelength. For example, the length (e.g., 10-17 μm) of the outer edge of light absorber  410  (e.g., the length of the longest edge of an absorbing surface of light absorber  410 ) can define the long-end wavelength (of the range) of light to be absorbed by light absorber  410 , and the distance (e.g., 0.65 μm) between adjacent holes in the mesh included in light absorbers  410  can define the short-end wavelength (of the range). In some examples, light absorbers  410  may not strongly absorb light having a wavelength that is longer than four times the length of its outer edge. In some examples, light absorber  410  may not strongly absorb light having a wavelength that is shorter than four times the distance between adjacent holes in the mesh included in light absorbers  410 . In some examples, light absorbers  410  can be configured to absorb light having wavelengths shorter than the length of its longest outer edge and longer than the length of an edge of a hole in the mesh included in light absorbers  410 . Although  FIGS. 4A-4C  illustrate each of the plurality of light absorbers as a mesh, examples of the disclosure can include a plurality of plate light absorbers (as illustrated in  FIGS. 4D-4F ) or a mix of mesh light absorbers and plate light absorbers. 
     In some examples, detector pixel  400  can further include a plurality of posts (e.g., post  440 ). Each light absorber of the plurality of light absorbers can include its own post, and the plurality of posts can be disposed at adjacent locations. For example, as illustrated in  FIGS. 4A-4C , the plurality of posts  440  can couple to sensor  420  through one or more electrical insulators  441  located at adjacent locations on a surface of sensor  420 . Further, post  440  coupled to each respective light absorber  410  can be disposed at a corner of light absorber  410 , and the plurality of light absorbers  410  can fan out in a four-petal configuration, as illustrated in  FIGS. 4A-4B . 
       FIGS. 4D-4F  illustrate top, plan, and cross-sectional views of an exemplary detector pixel  400  including a reflector  443  located between the light absorber and the sensor according to examples of the disclosure. Detector pixel  400  can be the same as the detector disclosed in  FIGS. 4A-4C . Detector pixel  400  can include a plurality of light absorbers, similar to detector pixel  400  illustrated in  FIGS. 4A-4C , but illustrated as plate absorbers. Detector pixel  400  can include a reflector  443 . Reflector can be any material configured to reflect a substantial amount (e.g., greater than 50%) of non-absorbed and/or incident light. Exemplary reflector materials can include, but are not limited to, Aluminum (Al) and Titanium (Ti). Reflector  443  can be configured as a mirror. In some examples, some of incident light transmits through light absorbers  410  (i.e., light not absorbed by light absorbers  410 ). Reflector  443  can redirect light back to light absorbers  410  to increase the amount of absorption of incident light by light absorbers  410 . 
     The plurality of light absorbers  410  can be thermally coupled to reflector  443  through a plurality of electrical insulators  441 , and reflector  443  can be thermally coupled to one or more sensors, such as sensor  420 . In some examples, a light absorber  410  can be configured to absorb at least a wavelength of light (e.g., light in the infrared spectrum). For example, as illustrated in  FIGS. 4D-4F , light absorber  410  can have a surface that faces reflector  443 . In some examples, the surface of light absorber  410  can be a distance from reflector  443 , such as a quarter of the wavelength of light to be absorbed by light absorber  410  (e.g., the first distance is a quarter of a wavelength of infrared light). In some examples, the distance between light absorbers  410  and reflector  443  being a quarter of a wavelength of light can create a resonant cavity effect between light absorbers  410  and reflector  443  for light of that wavelength. 
     Although  FIGS. 4D-4F  illustrate the plurality of absorbers as plate absorbers, examples of the disclosure are not so limited to plate absorbers, but can include any type of the absorber, such as the mesh absorbers illustrated in  FIGS. 4A-4C  and/or the polarized absorbers described with respect to  FIGS. 3A-3G . In some examples, detector pixel  400  can include a plurality of reflectors coupled to different light absorbers  410 . 
       FIGS. 4G-4I  illustrate top, plan, and cross-sectional views of an exemplary light detector including a reflector and multiple light absorbers according to examples of the disclosure. Detector pixel  400  can include a plurality of first light absorbers  410  and a second light absorber  412 . First light absorbers  410  and second light absorber  412  can be any material capable of absorbing light, including, but not limited to, NiCr, Phosphor Bronze, V x O y , and a-Si. In some examples, first light absorbers  410  and second light absorber  412  can include materials of the same composition. One skilled in the art would appreciate that the same material composition can include tolerances that result in a 15% deviation. In some examples, second light absorber  412  can be located closer to incident light than first light absorbers  410 . In some examples, first light absorbers  410  can be located closer to substrate  470  than second light absorber  412 . In some examples, light absorber  410 , second light absorber  412 , or both can have a large TCR and can be capable of detecting small or minute changes in temperature (e.g., a large resistance change per change in material temperature). 
     First light absorbers  410  can be thermally coupled to a sensor  420  through a plurality of posts  440 . Sensor  420  can be any type of sensor capable of measuring a change in temperature, such as a thermistor. In some examples, sensor  420  can be a resistor capable of changing a resistance in relation to changes in temperature experienced by first light absorbers  410 . 
     Posts  440  can include any type of material capable of conducting heat from first light absorbers  410  to sensor  420 . In some examples, posts  440  can be coupled to a third post  444 , which can couple to sensor  420 . In some examples, sensor  420  can be thermally coupled to first light absorbers  410  by a direct or indirect physical connection through which heat can conduct. For example, first light absorbers  410  can be directly coupled to sensor  420 , or heat may conduct through one or more intervening structures (e.g., third post  444 ) located between first light absorbers  410  and sensor  420  that are directly coupled to first light absorbers  410  and sensor  420 . 
     Detector pixel  400  can include a second light absorber  412 . In some examples, second light absorber  412  may not be included in the plurality of first light absorbers  410  that are thermally coupled to each other through sensor  420 . Second light absorber  412  can be thermally coupled to a second sensor  422  through second post  442 . Second sensor  422  can be mounted on substrate  470  and can be any type of sensor capable of measuring a change in temperature. In some examples, second sensor  422  can be a thermistor or a resistor. In some examples, sensor  420  and second sensor  422  have the same TCR. One skilled in the art would appreciate that the same TCR can include tolerances that result in a 15% deviation. In some examples, sensor  420  and second sensor  422  can be located on the same plane. 
     Second post  442  can include any type of material capable of conducting heat from second light absorber  412  to second sensor  422 . In some examples, second post  442  can transmit through one or more of the plurality of first light absorbers  410 . In some examples, as illustrated in  FIGS. 4A-4C , third post  444  (coupled to light absorbers  410  and posts  440 ) can be at a first position, and second post  442  (coupled to second light absorber  412 ) can be at a second position. The first position and the second position can be symmetric with respect to a center position halfway between first light absorbers  410  and second light absorber  412 . In some examples, second post  442  and third post  444  can be located at the corners of detector pixel  400 . 
     Second light absorber  412  can be configured to absorb at least a second wavelength of light longer than the first wavelength of light to be absorbed by first light absorbers  410  (and first light absorbers  410  can be configured not to absorb the second wavelength of light). For example, an outer edge of second light absorber  412  can be longer than an outer edge of first light absorbers  410 , and as a result, second light absorber  412  can absorb different or longer wavelengths of light than first light absorbers  410 . 
     In some examples, second light absorber  412  can have a surface that faces a reflector  443 , and the surface of second light absorber  412  can be a second distance (e.g., 2.5 um) from reflector  443 . In some examples, the second distance can be equal to (or within 10% from) a quarter of the second wavelength of light to be absorbed by second light absorber  412 . In some examples, the first distance (e.g., 0.65 um) being a quarter of the first wavelength of light (e.g., infrared or SWIR light) can create a resonant cavity effect between first light absorbers  410  and reflector  443  for light of that first wavelength. Similarly, the second distance being a quarter of the second wavelength of infrared light (e.g., extended SWIR or long-wave infrared (LWIR) light) may create a resonant cavity effect between second light absorber  412  and reflector  443  for light of that second wavelength. Although  FIGS. 4H-4I  illustrate the plurality of first light absorbers  410  thermally coupled to sensor  420  through reflector  443 , examples of the disclosure are not limited to thermally coupling sensor  420  through reflector  443 , but can also include examples where reflector  443  is omitted. In some examples, the plurality of first light absorbers  410  can be coupled to one or more electrical insulators, such as electrical insulator  441 . In some examples, the one or more electrical insulators  441  can be directly coupled to sensor  420  (similar to the configuration illustrated in  FIGS. 4A-4C ). 
     In some examples, second light absorber  412  can be included in an additional plurality of light absorbers. In some examples, the additional plurality of light absorbers can be different from the plurality of first light absorbers  410 . In some examples, each of the additional plurality of light absorbers can be electrically isolated from each other and can be thermally coupled to second sensor  422  to detect light of the second wavelength, as described above, longer than the first wavelength of light to be absorbed by first light absorbers  410 . 
       FIG. 4J  illustrates a plan view of an exemplary FPA or imager comprising an array of light sensing detector pixels according to examples of the disclosure. Detector pixel or detector pixel  400  can be included in FPA or imager  490 . An FPA can be an image-sensing device comprising an array of optical sensors. Detector pixel  400  can be incorporated as a first light sensing detector pixel (e.g., an infrared light sensing detector pixel) including a first light absorber, a second light absorber, a reflector, or any combination. In some examples, imager  490  can be an infrared imager. In some examples, the imager can comprise an array of detector pixels, where each detector pixel can be configured with a first light absorber and a second light absorber located on different layers. In some examples, imager  490  can be arranged as two rows and two columns. For example, detector pixel  400  can be co-located in a first column of a first row, while another detector pixel or detector pixel  400  can be co-located in a second column of the first row. Although  FIG. 4J  illustrates arrays of the same or repeated configuration of detectors or detector pixels, examples of the disclosure are not limited to detectors comprising arrays of the same or repeated configuration of detectors or detector pixels. In some examples, an array can include any combination of light detectors described herein, including any and/or all of the detectors illustrated in and described with respect to the other figures. 
     Any of the light absorbers describe here can be supported by and/or enclosed within an encapsulation layer. For example,  FIG. 4K-4M  illustrate cross-sectional views of exemplary detector pixels including encapsulation according to examples of the disclosure. Detector pixel  400  can include a plurality of light absorbers  410  (also labeled first light absorbers  410  in  FIG. 4M ). One or more of light absorbers  410  can include any of the light absorbers as discussed above, such as a mesh absorber (described above with respect to  FIGS. 4A-4C ), a plate absorber (described above with respect to  FIGS. 4D-4F ), or a polarizing absorber (similar to the absorbers described above with respect to  FIGS. 2A-2D and 3A-3G ). Plurality of light absorbers  410  can be at least partially encapsulated by encapsulation  445 . In some examples, plurality of light absorbers  410  can be fully encapsulated by encapsulation  445 . Encapsulation  445  can be configured for thermally coupling light absorbers  410  while also electrically isolating the light absorbers  410 . In some examples, encapsulation  445  can include a material transparent in the desired measurement wavelength(s). For example, the desired measurement wavelengths can include SWIR, and encapsulation  445  can include silicon dioxide SiO 2 , silicon nitride Si 3 N 4 , or both. In some examples, encapsulation  445  can be configured to prevent thermal expansion issues. For example, encapsulation  445  can have the same thermal expansion coefficient as the light absorbers  410 . Detector pixel  400  can further include reflector  443 . In some examples, any light (if any) absorbed by reflector  443  can be measured by sensor  420 . 
     When reflector  443  is thermally coupled to the plurality of light absorbers  410 , the sensitivity of detector pixel  400  can decrease.  FIG. 4L  illustrates a cross-sectional view of an exemplary detector pixel  400  including reflector  443  that can be thermally isolated from the plurality of light absorbers  410 . Thermal isolation can prevent light absorption or heat generated by the plurality of light absorbers from affecting reflector  443 . Reflector  443  can be coupled to structure  449 . Structure  449  can be configured to provide support to reflector  443 . In some examples, structure  449  can be coupled to contact  430  and contact  432 . In some examples, structure  449  can be decoupled from contact  430  and contact  432 . In some examples, structure  449  can be configured to act as a heat sink to prevent reflector  443  from changing temperature due to any absorbed light. 
     In some examples, a detector pixel can include multiple layers of absorbers.  FIG. 4M  illustrates a cross-sectional view of an exemplary detector pixel  400  including a first layer including a plurality of first light absorbers  410  encapsulated by encapsulation  445 . Detector pixel  400  can also include a second layer including a plurality of second light absorbers  412  encapsulated by encapsulation  447 . In some examples, the plurality of first light absorbers  410  can be located closer to substrate  470  than the plurality of second light absorbers  412 . The plurality of first light absorbers  410  can optionally include encapsulation  445  disposed on or around the plurality of first light absorbers  410 . Although not illustrated in the figure, the plurality of second light absorbers  412  can include encapsulation  447  disposed on or around the plurality of first light absorbers  412 . In some examples, encapsulation  447  and encapsulation  445  can comprise the same materials. In some examples, the encapsulation disposed on or surrounding the light absorbers can comprise a different material than the encapsulation disposed closer to the substrate than the light absorbers. 
     In some examples, the plurality of second light absorbers  412  can be configured to absorb one or more longer wavelengths than the plurality of first light absorbers  410 . In some examples, the plurality of first light absorbers  410  can be configured to absorb one or more shorter wavelengths than the plurality of second light absorbers  412 . In some examples, the layer including the plurality of first light absorbers  410  can be spaced a distance equal to a quarter of the absorption wavelength away from reflector  443 . In some examples, the layer including the plurality of second light absorbers  412  can be spaced a distance equal to a quarter of the absorption wavelength away from the layer including the plurality of first light absorbers  410 . 
     In some examples, the properties (e.g., size) of the light absorbers can be configured based on the desired measurement (e.g., absorption) wavelength range. As discussed earlier, one or more of the light absorbers can be configured with an outer edge equal to four times the long-end wavelength of the desired measurement wavelength range. In some examples, the plurality of first light absorbers  410  can be configured with a desired measurement wavelength range that is longer than the desired measurement wavelength range of the plurality of second light absorbers  412  by configuring the outer edge of the plurality of first light absorbers to be longer than the outer edge of the plurality of second light absorbers  412  (as illustrated in  FIG. 4M ). In this manner, the overall desired measurement wavelength range of detector pixel  400  can be extended. 
     In some examples, light absorbers (e.g., plurality of light absorbers  412 ) on a first layer can have a size different from light absorbers (e.g., plurality of light absorbers  410 ) on a second layer. Although  FIGS. 4K-4M  illustrate detector pixels including reflector  443 , examples of the disclosure can include detectors without a reflector. Although  FIG. 4M  illustrates a detector pixel including two layers of light absorbers, examples of the disclosure can include any number of layers, including, but not limited to, three layers. 
     In some examples, the encapsulation can provide support to a polarization-sensitive light absorber such as those shown in  FIGS. 2A-2D and 3A-3G .  FIG. 4N  illustrates a top view of an exemplary detector pixel according to examples of the disclosure. In some examples, encapsulation  445  can support a plurality of light absorbers  410  that can be collectively configured to absorb light in a given polarizing direction. In some examples, light absorber  410  can be linear. In some examples, the light absorbers  410  can be spaced at intervals (e.g., equivalent to slits  250  illustrated in  FIGS. 2A-2D  and slits  350  illustrated in  FIGS. 3A-3G ). Light absorber  410  can be supported by encapsulation  445 . Due to the encapsulation providing support, ends of the plurality of light absorbers  410  can be configured closer to the edges of encapsulation  445  (in contrast to ends of slit  350  included in first light absorber  310  illustrated in  FIG. 3D , for example). In some examples, a length of light absorber  410  can be equal to a length of encapsulation  445 . In some examples, at least one edge of light absorber  410  can be aligned with at least one edge of encapsulation  445 . By configuring the ends of plurality of light absorber  410  closer to edges of encapsulation  445  (e.g., the material on two opposite edges of the absorber is less than the material on the other two opposite edges), less light can be absorbed in other polarizing directions, such as second polarizing direction  462 , and thus, the measurement from the plurality of light absorbers  410  can include less light absorbed from different polarization directions. 
     Although the figure illustrates the plurality of light absorbers  410  as rectangular, examples of the disclosure can include any shape, such as, but not limited to, squares, hexagons, heptagons, and circles.  FIG. 4O  illustrates a top view of an exemplary detector pixel according to examples of the disclosure. In some examples, the detector pixel can include square light absorbers  410 . In some examples, encapsulation  445  can provide support to the material forming the light absorber  410 , such that one or more edges of light absorbers  410  can be aligned with at least one edge of encapsulation  445 . 
     As discussed above, a detector capable of operating at, near, or above room temperature may be desired. Depending on the application or use, the detector can be incorporated into a system that is exposed to different environmental conditions, such as environments with temperatures above room temperature. As the temperature increases, the sensitivity of the detector and/or associated ROIC can decrease. Accordingly, a detector and/or ROIC can be optimized for a specific operation range, where performance of the sensor system (i.e., a system including at least a detector and a ROIC) can worsen for detection outside of that operation range. 
     One figure of merit for sensor systems can be the dynamic range. The dynamic range can be the maximum light or photon flux that can be sensed by the ROIC in the sensor system. A system whose performance is not limited by its sensitivity while operating throughout the dynamic range can be desired. Related to the sensitivity can be the TCR. As discussed above, the TCR can be a measure of the change in resistance in response to a change in temperature. The TCR can be related to the resistance by:
 
 R=Ae   TCR×T    (2)
 
where R is the resistance, A is a coefficient, and T is the operating temperature. Alternatively, the TCR can be determined by:
 
                   TCR   =       1   R     ⁢     dR   dT               (   3   )               
Equation 2 illustrates that the TCR is not constant, and instead, is a function of the operating temperature. For example, a V x O y -based bolometer can be a good candidate for room temperature operation because the TCR can have a maximum or an absolute value (e.g., −0.003K −1 ) at or near room temperature (e.g., 300K). However, as the operating temperature increases, the change in resistance can decrease. As a result, under high flux light conditions, the bolometer or detector and its integrated circuit or ROIC can be less sensitive to temperature or resistance changes. Accordingly, a sensory system (e.g., bolometer and integrated circuit or ROIC) capable of a wide dynamic range and capable of adjusting its sensitivity to account for both low flux light (i.e., incident light less than a flux threshold value) and high flux light (i.e., incident light greater than or equal to a flux threshold value) conditions can be desired.
 
       FIG. 5  illustrates an exemplary ROIC according to examples of the disclosure. ROIC  500  can comprise a plurality of unit cells  510 . Each unit cell  510  in ROIC  500  can be coupled to a detector pixel  530  included in a detector array. A unit cell  510  can convert a photocurrent generated by each detector pixel  530  (coupled to Vdetcom  540 ) to a voltage indicative of the properties of detected light. A unit cell  510  can comprise an integrator, a preamplifier, a sample &amp; hold (SH) circuit, and an analog-to-digital converter (ADC). In some examples, the current from detector pixel  530  can be weak or small, incremental current. One way to generate a large measurable output from the small, incremental current can be to integrate the photocurrent using an integrating capacitor C int    520 . Integrating capacitor C int    520  can be coupled to a detector pixel  530  in the detector array. The integrating capacitor C int    520  can be configured to store charge associated with the photocurrent or light detected by the corresponding detector pixel  530 . The integrating capacitor C int    520  can be coupled to an amplifier  560 . An integration time can be set to determine the fixed period of time when the photocurrent from detector pixel  530  can be integrated. At the end of the integration time, C int  can be proportional to the current and can represent incident light on detector pixel  530 . A reset transistor  550  can be coupled to the integrating capacitor C int    520  to discharge the capacitor. At the end of the integration time, the integrated voltage can be sampled and held on a hold capacitor C SH    522  through transistor SH  552 . The hold capacitor C SH    522  can be configured to store the integrated charge. 
     The ROIC can have a row-column arrangement where each unit cell  510  in a row can be coupled to the same row select lines  544 , and each unit cell  510  in a column can be coupled to the same column select lines  546 . Row select lines  544  can be coupled to RowSel  554  transistor, and column select lines  546  can be coupled to ColSel  556  transistor. The outputs of unit cells  510  can be swept row-by-row and/or column-by-column to be converted to a serial stream of bits. The sequence of row and column selection can be enabled and varied depending on the type of mode of integration (e.g., Integrate-While-Read or Integrate-Then-Read). If a unit cell  510  is selected (through a row select line  544  turning on a corresponding RowSel  554  transistor and column select line  546  turning on a corresponding ColSel  556  transistor), the integrated charge stored on the hold capacitor C SH  can be input into ADC  532 . ADC  532  can digitize the integrating current and can transmit this information to processor  562 . 
     In some examples, the ROIC can be optimized with a specific gain or specific mode of operation. However, when imaging a scene, for example, the scene can include both bright (e.g., high photon flux) objects of interest and dim (e.g., low photon flux) objects of interest. Therefore, a specific gain or specific mode of operation optimized for the bright objects of interest can prevent sufficient detection of the dim objects of interest. Additionally, a specific gain or specific mode of operation optimized for dim objects can lead to saturation of the integrating capacitors C int    520  and/or ADCs  532  in ROIC  500 . In some examples, the bright objects of interest can include the reflection of light due to one or more properties in the object. In some examples, the dim objects of interest can include the reflection of light due to other properties in the object. For a given dynamic range for the detector, the ROIC, or both, the sensor system&#39;s performance can be compromised when operating outside this given dynamic range. The dynamic range can limit how fast the data or stored charge can be read by the processor, which can be important especially when imaging moving objects. Therefore, a detector and ROIC capable of a wide or ultra-wide dynamic range can be desired. 
       FIGS. 6A-6B  illustrate top and cross-sectional views of an exemplary detector pixel including multiple absorbers according to examples of the disclosure. Detector pixel  600  can be a detector pixel including a first light absorber  610 . In some examples, detector pixel  600  can be a bolometer. First light absorber  610  can include any material capable of absorbing light, including, but not limited to, NiCr, Phosphor Bronze, V x O y , and a-Si. First light absorber  610  can be exposed to the electromagnetic radiation or light, and any light absorbed by first light absorber  610  can produce heat within the light absorber, changing its temperature. The change in temperature in first light absorber  610  can be proportional to the amount of light absorbed by first light absorber  610 . In some examples, first light absorber  610  can have a large TCR and can be capable of detecting small or minute changes in incident radiation (e.g., a large resistance change per change in material temperature). First light absorber  610  can be thermally coupled to a first sensor  620  through first post  640 . First sensor  620  can be mounted on a substrate  670  and can be any type of sensor capable of measuring a change in temperature, such as a thermistor. In some examples, first sensor  620  can be a resistor capable of changing a resistance in relation to changes in temperature experienced by first light absorber  610 . 
     First post  640  can include any type of material capable of conducting heat from first light absorber  610  to first sensor  620 . In some examples, first light absorber  610  can be coupled to one post. In some examples, first light absorber  610  can be coupled to multiple posts. In some examples, first sensor  620  can be thermally coupled to first light absorber  610  by a direct or indirect physical connection through which heat can conduct. For example, first light absorber  610  can be directly coupled to first sensor  620 , or heat may conduct through one or more intervening structures located between first light absorber  610  and first sensor  620  that are directly coupled to first light absorber  610  and first sensor  620 . 
     Substrate  670  can include contact  630  and contact  631 . Contact  630  and contact  631  can be coupled to an integrated circuit, such as a ROIC. The integrated circuit can be coupled to a processor or controller. In some examples, the processor can bias the detector with a constant current or constant voltage and can measure the change in resistance through contact  630  and contact  631  due to light impinging on first light absorber  610 . 
     Detector pixel  600  can further include a second light absorber  612 . Second light absorber  612  can include any material capable of absorbing light, including, but not limited to, NiCr, Phosphor Bronze, V x O y , and a-Si. In some examples, the material of second light absorber  612  can include the same material composition as the material of first light absorber  610 . One skilled in the art would appreciate that the same material composition can include tolerances that result in a 15% deviation. Second light absorber  612  can be located further away from the incident radiation or light than first light absorber  610 . Second light absorber  612  can be exposed to light, and any light absorbed by second light absorber  612  can produce heat within the light absorber, changing its temperature. The change in temperature in second light absorber  612  can be proportional to the amount of light absorbed by second light absorber  612 . Second light absorber  612  can be thermally coupled to a second sensor  622  mounted on substrate  670 . The change in temperature in second light absorber  612  can cause a change in the resistance of second sensor  622 . In some examples, second sensor  622  can be a resistor that changes resistance as its temperature changes. Second sensor  622  can be electrically coupled to an integrated circuit (not shown) through contact  632  and contact  633 . Second sensor  622  can be coupled to the same unit cell in the integrated circuit that first sensor  620  is coupled to. The integrated circuit can be coupled to a processor, computer, or controller, which can bias the detector pixel with a constant current or constant voltage and can measure the change in resistance through contact  632  and contact  633  due to the light impinging on second light absorber  612 . 
     In some situations, a detector may not include a second light absorber  612  located further away from incident light than first light absorber  610  (i.e., the first light absorber can be located between incident light and the second light absorber). In such situations, the intensity of incident light on first light absorber  610  can be outside the dynamic range of first light absorber  610 . Without second light absorber  612 , the capabilities of the sensor system can be limited to the dynamic range of first light absorber  610 . First light absorber  610  may only be capable of absorbing an amount less than 100% of incident light, which can saturate the sensor system and can leave the remaining unabsorbed incident light undetected. While saturation of the sensor system can be avoided by reducing the intensity of incident light, for example, reducing the intensity of the emitted light from the light source can lead to a compromise in the capability of detecting low flux light. That is, reducing the intensity of the emitted light from the light source can cause reflection or transmission of very low flux light that may not be detected by the detector. 
     Detector pixel  600  can be capable of measuring both low flux light and high flux light by including a second light absorber  612  that can “shadow” first light absorber  610  or can be exposed to any incident radiation or incident light not absorbed by first light absorber  610 . For high flux situations, for example, the flux of incident light can saturate first light absorber  610  and corresponding integrated circuit. The processor coupled to the integrated circuit can ignore the signal (or photocurrent) from first light absorber  610 , for example. If incident light saturates first light absorber  610  (i.e., exceeds the absorption capabilities of first light absorber  610 ) and/or corresponding unit cell (e.g., unit cell  510  of ROIC  500  illustrated in  FIG. 5 ), incident light can still be measured by second light absorber  612  and its corresponding unit cell. For low flux light situations, for example, first light absorber  610  can absorb all or greater than 50% of incident light, while no or small amounts (e.g., less than 50%) of incident light may reach second light absorber  612 . If the integrated circuit coupled to first light absorber  610  has not saturated, the processor can ignore the signal (or photocurrent) from second light absorber  612  and determine the measurement based on first light absorber  610 . 
     Any number of configurations for first light absorber  610  and second light absorber can be used for measuring low flux light, high flux light, or both. To “shadow” first light absorber  610 , at least a portion of second light absorber  612  can overlap at least a portion of first light absorber  610  and can be located closer to substrate  670  than first light absorber  610 . Second light absorber  612  can absorb a portion of the total incident light, where less than the total incident light can reach second light absorber  612  than first light absorber  610 . For example, first light absorber  610  can be configured to absorb 80% of the relative absorption (i.e., absorbed incident light or light incident on the surface area of the light absorbers that is absorbed by the light absorbers), whereas second light absorber  612  can be configured to absorb 20% of the relative absorption. In some examples, first light absorber  610  can be the same size and/or same shape as second light absorber  612 . One skilled in the art would appreciate that the same size and same shape can include tolerances that result in a 15% deviation. In some examples, first light absorber  610  and second light absorber  612  can be different sizes. In some examples, the size of first light absorber  610  can be greater than second light absorber  612 . In some examples, contact  630  and contact  631  (coupled to first light absorber  610 ) and contact  632  and contact  633  (coupled to second light absorber  612 ) can couple to a separate unit cell (e.g., unit cell  510 ) in the integrated circuit (e.g., ROIC), essentially forming two detector pixels having the same footprint as a detector pixel. In some examples, the absorbance of first light absorber  610  can be based on the targeted transmittance of shadowed light to second light absorber  612 . In some examples, the sensitivity of first light absorber  610  can differ from the sensitivity of second light absorber  612 . For example, a second light absorber  612  (and corresponding unit cell on the ROIC) can be configured with a higher sensitivity than first light absorber  610  (and corresponding unit cell on the ROIC). By configuring different sensitivities, the sensor system can be capable of high sensitivity detection throughout the (wide) dynamic range. In some examples, first light absorber  610  can be coupled to a first post  640  that transmits through second light absorber  612 , while first light absorber  610  and second light absorber  612  can remain thermally isolated from each other. First light absorber  610  can be thermally coupled to first sensor  620  through first post  640 . Second light absorber  612  can include a second post  642 , and second light absorber  612  can be thermally coupled to second sensor  622  through second post  642 . 
     In some examples, as illustrated in  FIGS. 6A-6B , first post  640  (coupled to first light absorber  610 ) can be at a first position, and second post  642  (coupled to second light absorber  612 ) can be at a second position. The first position can be located at one corner of detector pixel  600 , and the second position can be located at another corner of detector pixel  600 . In some examples, the first position and the second position can be symmetric with respect to a center position halfway between first light absorber  610 , second light absorber  612 , or detector pixel  600 . In some examples, the heat capacity of first post  640  can be different from the heat capacity of second post  642  and/or can be based on the size, absorbance, or properties of the light absorbers. In some examples, contact  630  and contact  631  (coupled to first light absorber  610 ) can be directly or indirectly coupled to contact  632  and contact  633  (coupled to second light absorber  612 ). 
     In some examples, first post  640  and first sensor  620  (coupled to first light absorber  610 ) and second post  642  and second sensor  622  can be configured with a low heat capacity such that the temperature greatly increases for a small amount of incident radiation or light flux. In some examples, the signal-to-noise ratio (SNR) of second light absorber  612  can be comparable to the SNR of first light absorber  610 . As a result, the signal from second light absorber  612  can be used to improve the SNR of the measurement, especially when the noise on the signal coupled to first light absorber  610  can be averaged and/or is dominated by an element not related to detector pixel  600 . 
     Although  FIGS. 6A-6B  illustrate the plurality of absorbers as plate absorbers, examples of the disclosure are not so limited to plate absorbers, but can include any type of the absorber, such as the mesh absorbers illustrated in  FIGS. 4A-4C  and/or the polarized absorbers described with respect to  FIGS. 3A-3G . In some examples, each of first light absorber  610  and second light absorber  612  can be a mesh, and can together form a capacitive resonant mesh. In some examples, each light absorber can include a grid of wires forming the mesh. For example, as illustrated in  FIGS. 4A-4C , the light absorbers can be coplanar and can form a capacitive resonant mesh such that the light absorbers only absorb light in a range of wavelengths determined by the spacing of the wires in the metal mesh and the dimensions of the light absorber themselves. Although  FIGS. 6A-6B  illustrate two light absorbers, examples of the disclosure can include any number of light absorbers and corresponding sensors, posts, and contacts. Additionally, examples of the disclosure can include one or more reflectors, one or more electrical insulators coupled to one or more posts, or both. 
     In some examples, detector pixel  600  can include a third light absorber  614 , as illustrated in  FIG. 6C . Third light absorber  614  can be thermally coupled to first post  640 . In some examples, bright objects can lead to bright (i.e., high intensity) incident light on the surface of first light absorber  610 , second light absorber  612 , or both. The high intensity incident light can lead to a bias current that causes an excessive load (i.e., overload) on the sensor system associated with detector pixel  600 . To prevent the bias current from overloading the sensor system, third light absorber  614  can be configured as a heat sink. In some examples, third light absorber  614  can include a material with the same composition as first light absorber  610 , second light absorber  612 , or both. In some examples, the resistivity of third light absorber  614  can be less than the resistivity of first light absorber  610 , second light absorber  612 , or both. In some examples, the resistivity of third light absorber can be 1/10th the resistivity of first light absorber  610 , second light absorber  612 , or both. In some examples, third light absorber  614  can be thermally coupled to second post  642 . In some examples, inclusion of the third light absorber  614  can lead to a loss of sensitivity, but can also lead to a wider dynamic range. 
       FIGS. 7A-7B  illustrate exemplary top and cross-sectional views of a detector pixel including multiple absorbers according to examples of the disclosure. 
     Detector pixel  700  can be a detector pixel including a first light absorber  710  and a second light absorber  712 . First light absorber  710  and second light absorber  712  can include any material, such as NiCr, Phosphor Bronze, V x O y , and a-Si, capable of absorbing light. First light absorber  710  and second light absorber  712  can be exposed to electromagnetic radiation or incident light, and any light absorbed by the light absorber can produce heat within the light absorber, changing its temperature. The change in temperature in first light absorber  710  can be proportional to the amount of light absorbed in first light absorber  710 , and the change in temperature in second light absorber  712  can be proportional to the amount of light absorbed in second light absorber  712 . In some examples, first light absorber  710  and second light absorber  712  can include materials of the same composition. One skilled in the art would appreciate that the same material composition can include tolerances that result in a 15% deviation. In some examples, first light absorber  710  can be located on the same layer or plane as second light absorber  712 . In some examples, third light absorber  714  can be located closer to incident light than first light absorber  710 , second light absorber  712 , or both. In some examples, first light absorber  710 , second light absorber  712 , or both can be located closer to substrate  770  than third light absorber  714 . In some examples, first light absorber  710 , second light absorber  712 , or both can have a large TCR and can be capable of detecting small or minute changes in temperature (e.g., a large resistance change per change in material temperature). 
     First light absorber  710  can be thermally coupled to a first sensor  720  through first post  740 . Second light absorber  712  can be thermally coupled to a second sensor  722  through second post  742 . Both first sensor  720  and second sensor  722  can be mounted on a substrate  770  and both sensors can be any type of sensor capable of measuring a change in temperature. In some examples, first sensor  720 , second sensor  722 , or both can be a thermistor. In some examples, first sensor  720 , second sensor  722 , or both can be a resistor capable of changing a resistance in relation to changes in temperature experienced by the corresponding light absorber. 
     First post  740  and second post  742  can include any type of material capable of conducting heat from the corresponding light absorber to the corresponding sensor. In some examples, one or more of first light absorber  710  and second light absorber  712  can be coupled to one post. In some examples, one or more of first light absorber  710  and second light absorber  712  can be coupled to multiple posts. In some examples, first sensor  720 , second sensor  722 , or both can be thermally coupled to first light absorber  710  or second light absorber  712 , respectively, by a direct or indirect physical connection through which heat can conduct. For example, first light absorber  710  can be directly coupled to first sensor  720 , or heat may conduct through one or more intervening structures located between first light absorber  710  and first sensor  720  that are directly coupled to first light absorber  710  and first sensor  720 . 
     Substrate  770  can include contact  730  and contact  731  coupled to first light absorber  710 . Substrate  770  can also include contact  732  and contact  733  coupled to second light absorber  712 . Contact  730 , contact  731 , contact  732 , and contact  733  can be coupled to an integrated circuit, such as a ROIC. The integrated circuit can be coupled to a processor or controller. In some examples, the processor can bias the detector with a constant current or constant voltage and can measure the change in resistance through the contacts due to the light impinging on the light absorber. In some examples, at least one contact (e.g., contact  730  or contact  731 ) coupled to first light absorber  710  and at least one contact (e.g., contact  732  or contact  733 ) coupled to second light absorber  712  can be coupled to a common voltage, such as Vdetcom. In some examples, contact  730  or contact  731  and contact  732  or contact  733  can be coupled to the same biasing voltage source. In some examples, contact  730  or contact  731  and contact  732  or contact  733  can be coupled to the same circuitry or unit cell on the integrated circuit (e.g., ROIC). 
     In some examples, first light absorber  710  and second light absorber  712  can have the same optical properties. For example, first light absorber  710  and second light absorber  712  can include the same physical properties (e.g., material compositions, sizes, shapes, or any combination). One skilled in the art would appreciate that the same material compositions, same size, and same shape can include tolerances that result in a 15% deviation. In some examples, first light absorber  710  and second light absorber  712  can be coupled to the same sensor and/or contacts. 
     In some situations, a detector pixel can include a plurality of light absorbers, where the plurality of light absorbers can have the same dimensions. For example, a detector pixel can include two light absorbers, each occupying 50% of the footprint of detector pixel  700 . Such a configuration can prevent saturation in situations of high flux light. However, the fill factor, equal to the area of the light sensitive area of the detector pixel to the total detector pixel area, can be poor or inefficient. 
     To prevent saturation in the situations of high flux light and to prevent inefficient fill factor, detector pixel  700  can include third light absorber  714 . Third light absorber  714  can be different from at least one of first light absorber  710  and second light absorber  712 . For example, third light absorber  714  can have different size, form factor, heat capacity, and/or type of material than first light absorber  710 , second light absorber  712 , or both. 
     Third light absorber  714  can be thermally coupled to a third sensor  724  through third post  744 . Third sensor  722  can be mounted on a substrate  770  and can be any type of sensor, such as a thermistor or resistor, capable of measuring a change in temperature. In some examples, third sensor  724  can have the same optical properties as first sensor  720 , second sensor  722 , or both. One skilled in the art would appreciate that the same optical properties can include tolerances that result in a 15% deviation. Third post  744  can include any type of material capable of conducting heat from third light absorber  714  to third sensor  724 . In some examples, third light absorber  714  can be coupled to one post. In some examples, third light absorber  714  can be coupled to multiple posts. Third sensor  724  can be electrically coupled to an integrated circuit (not shown) through contact  734  and contact  735 . The integrated circuit can be coupled to a processor, computer, or controller, which can bias the detector pixel with a constant current or constant voltage and can measure the change in resistance through contact  734  and contact  735  due to light impinging on third light absorber  714 . 
     In some examples, third light absorber  714  can be non-overlapping with first light absorber  710 , second light absorber  712 , or both. By configuring the light absorbers to be non-overlapping and spatially co-located, the light absorbers can collect all or a substantial amount of the photons from incident light. This can be unlike the situation where overlapping at least a portion of the light absorbers can risk losing photons from being incident on one or more light absorbers. In some examples, third light absorber  714  can be located closer to incident light than first light absorber  710 , second light absorber  712 , or both. In some examples, first light absorber  710 , second light absorber  712 , or both can be located closer to substrate  770  than third light absorber  714 . 
     Due to the smaller size, for example, third light absorber  714  can be exposed to a lower percentage of the total incident light than first light absorber  710 , second light absorber  712 , or both. In some examples, the proportion of the relative sizes of the light absorbers can be equivalent to the proportion of incident light absorbed by each absorber. For example, first light absorber  710  can occupy 40% of the footprint of detector pixel  700 , second light absorber  712  can occupy 40% of the footprint, and third light absorber  714  can occupy 20% of the footprint. As a result, first light absorber  710  and second light absorber  712  can each absorb 40% of incident light, and third light absorber  714  can absorb 20% of incident light. In some examples, third light absorber  714  can “shadow” a portion of at least one first light absorber  710  and second light absorber  712 . For example, incident light not absorbed by third light absorber  714  can be incident on first light absorber  710  or second light absorber  712 . 
     In some examples, the same configuration can be used to detect both high flux light and low flux light. For high flux light situations, for example, a portion of light can be absorbed by first light absorber  710 , a portion of light can be absorbed by second light absorber  712 , and a portion of light can be absorbed by third light absorber  714 . Since different portions of light can be absorbed by different light absorbers, saturation of any one light absorber can be prevented. For low flux light situations, in some examples, first light absorber  710 , second light absorber  712 , third light absorber  714 , or any combination of light absorbers can absorb light. 
     Although  FIGS. 7A-7B  illustrate three light absorbers, examples of the disclosure can include any number of light absorbers. Additionally, although the figures illustrate the three light absorbers as non-overlapping, examples of the disclosure can include one or more light absorbers that overlap (i.e., light not absorbed by one slight absorber can be incident on another light absorber) at least in part. In some examples, first light absorber  710  and second light absorber  712  can be concentric with third light absorber  714  shadowing or overlapping a portion of first light absorber  710  and second light absorber  712 . In some examples, detector pixel  700  can include a fourth light absorber thermally coupled to first post  740  or second post  742  to prevent overloading of the sensor system due to a high bias current. 
       FIGS. 8A-8B  illustrate exemplary top and cross-sectional views of a detector pixel including multiple absorbers with different sizes according to examples of the disclosure. Detector pixel  800  can include a first light absorber  810  and a second light absorber  812 . First light absorber  810  and second light absorber  812  can be any material capable of absorbing light, including, but not limited to, NiCr, Phosphor Bronze, V x O y , and a-Si. In some examples, first light absorber  810  and second light absorber  812  can include materials of the same composition. One skilled in the art would appreciate that the same material composition can include tolerances that result in a 15% deviation. In some examples, first light absorber  810 , second light absorber  812 , or both can have a large TCR and can be capable of detecting small or minute changes in temperature. Although  FIGS. 8A-8B  illustrate two light absorbers, examples of the disclosure can include any number of light absorbers. 
     First light absorber  810  can be thermally coupled to a first sensor  820  through first post  840 . Second light absorber  812  can be thermally coupled to a second sensor  822  through second post  842 . First sensor  820  and second sensor  822  can be any type of sensor capable of measuring a change in temperature, such as a thermistor. In some examples, first sensor  820 , second sensor  822 , or both can be a resistor capable of changing a resistance in relation to changes in temperature experienced by the corresponding light absorber. 
     First post  840  can include any type of material capable of conducting heat from first light absorber  810  to first sensor  820 . Second post  842  can include any type of material capable of conducting heat from second light absorber  812  to second sensor  822 . In some examples, first light absorber  810 , second light absorber  812 , or both can be coupled to one post. In some examples, first light absorber  810 , second light absorber  812 , or both can be coupled to multiple posts. In some examples, first sensor  820  can be thermally coupled to first light absorber  810  by a direct or indirect physical connection through which heat can conduct. Similarly, second sensor  822  can be thermally coupled to second light absorber  812  by a direct or indirect physical connection through which heat can conduct. For example, first light absorber  810  can be directly coupled to first sensor  820 , or heat may conduct through one or more intervening structures located between first light absorber  810  and first sensor  820  that are directly coupled to first light absorber  810  and first sensor  820 . 
     Substrate  870  can include contact  830 , contact  831 , contact  832 , and contact  833 . Contact  830  and contact  831  can be configured to couple first sensor  820  to an integrated circuit, such as a ROIC. Similarly, contact  832  and contact  833  can be configured to couple second sensor  822  to the integrated circuit. The integrated circuit can be coupled to a processor or controller. In some examples, the processor can bias the detector with a constant current or constant voltage and can measure the change in resistance due to light impinging on the light absorber. In some examples, at least one contact (e.g., contact  830  or contact  831 ) coupled to first light absorber  810  and at least one contact (e.g., contact  832  or contact  833 ) coupled to second light absorber  812  can be coupled to a common voltage, such as Vdetcom. In some examples, contact  830  or contact  831  and contact  832  or contact  833  can be coupled to the same biasing voltage source. In some examples, contact  830  or contact  831  and contact  832  or contact  833  can be coupled to the same circuitry or unit cell on the integrated circuit (e.g., ROIC). 
     In some examples, first light absorber  810  and second light absorber  812  can have the same optical properties and/or physical properties. One skilled in the art would appreciate that the same optical properties can include tolerances that result in a 15% deviation. For example, first light absorber  810  and second light absorber  812  can include materials of the same composition and/or can have the same sizes. In some examples, first light absorber  810  and second light absorber  812  can be located on the same layer or plane. In some examples, first light absorber  810  and second light absorber  812  can be located on different layers or planes. 
     To prevent saturation (e.g., in situations of high flux light), first light absorber  810  can have one or more properties different from second light absorber  812 . In some examples, first light absorber  810  can be greater in size than second light absorber  812 . In some examples, first light absorber  810  and second light absorber  812  can occupy at least 80% of a full area of detector pixel  800 , while maintaining electrical isolation and/or thermal isolation between the first light absorber and the second light absorber. Due to the smaller size, second light absorber  812  can be exposed to a lower percentage of the total incident light than first light absorber  810 . In some examples, the proportion of the relative sizes of the light absorbers can be equivalent to the proportion of incident light absorbed by each absorber. For example, first light absorber  810  can occupy 80% of the footprint of detector pixel  800 , and second light absorber  812  can occupy 20% of the footprint. First light absorber  810  can absorb 80% of the relative absorption (i.e., absorbed incident light or light incident on the surface area of the light absorbers that is absorbed by the light absorbers), and second light absorber  812  can absorb 20% of the relative absorption. In some examples, first light absorber  810  and second light absorber  812  are located such that neither absorber shadows (e.g., blocks from direct incident light) the other absorber, which can reduce number of steps in the fabrication process. Other exemplary properties that may be different between the light absorbers can include, but are not limited to, heat capacity, form factors, and type of material. 
     In some examples, the same configuration can be used to detect both high flux light and low flux light. For high flux situations, for example, a portion of light can be absorbed by first light absorber  810 , and a portion of light can be absorbed by second light absorber  812 . Since the absorption of light can be distributed among multiple light absorbers instead of being concentrated onto one light absorber, saturation of any one light absorber can be prevented. For low flux light situations, in some examples, first light absorber  810 , second light absorber  812 , or both can absorb light. 
     In some examples, the integrated circuit can read the photocurrent from first light absorber  810  at a different time from reading the photocurrent from second light absorber  812 . In some examples, the integrated circuit can read the photocurrent from first light absorber  810  and second light absorber  812  at the same time, especially utilizing the total photocurrent from both light absorbers. In some examples, detector pixel  800  can include a third light absorber thermally coupled to first post  840  or second post  842  to prevent overloading of the sensor system due to a high bias current. 
     Although the exemplary detectors illustrated in the figures are illustrated as a single layer or two layer light absorbers, examples of the disclosure can include any number of layers and any number of absorbers. Furthermore, any or all of the detectors illustrated in the figures (e.g., detector pixel  600 , detector pixel  700 , and detector pixel  800 ) can be included in an imager. 
     Conventionally, bolometers have been tuned for a pre-determined flux range or time constant at the time of manufacture. However, without knowledge of the flux level beforehand, the pre-determined time constant may not be optimal for a given application. Therefore, tuning the time constant of the detector, which can affect the sensitivity, can be ideal, even for detectors with a wide dynamic range. The time constant of the detector can be an indication of how fast the detector can respond to incident light. The time constant can be a thermal time constant equal to the ratio of the heat capacity (i.e., ratio of the difference in heat from incident light to the resultant change in heat of the light absorber) of the light absorber to the thermal conductance (i.e., the rate of heat conduction). A faster time constant can result from a high thermal conductance, which can lead to a decrease in sensitivity and a slower response time. Conversely, a slower time constant can result from a low thermal conductance, which can lead to an increase in sensitivity and a faster response time. By tuning the time constant of the detector, the detector can be optimized after manufacture for different flux levels, or the detector can be electrostatically tuned for the range or level of flux that it is receiving. 
       FIG. 9A  illustrates a plan view of a portion of an exemplary detector capable of electrostatically tuning according to examples of the disclosure. Detector pixel  900  can include a sensor  920  can be coupled to a plurality of structures or legs  980 . Sensor  920  and plurality of structures or legs  980  can be referred to as the body. Structures or legs  980  can be any material capable of supporting sensor  920 . In some examples, structures or legs  980  can be electrically conductive. In some examples, plurality of structures or legs  980  can be electrically conductive spring structures or legs. In some examples, plurality of structures or legs  980  can be coupled to a plurality of contacts, such as contact  930 , contact  931 , contact  932 , and contact  933 . In some examples, sensor  920  can include four structures or legs coupled to four contacts. Two of the contacts (e.g., contact  930  and contact  932 ) can be coupled to an integrated circuit, such as a ROIC. One of the contacts (e.g., contact  931  or contact  933 ) can be coupled to a voltage or current source to electrically charge the body, as will be discussed below. Another contact can be used as another electrical conductor and/or can be used for mechanical support. The four structures or legs  980  can be used to maintain sensor  980  on the same plane (i.e., sensor  980  does not tilt, turn, or flip) as sensor  980  (or body) is electrostatically attracted to conductive plate  976 , as will be discussed below. 
     Detector pixel  900  can further include a substrate  972 .  FIG. 9B  illustrates a plan view of a portion of an exemplary detector illustrating a substrate configured as an electrostatic capacitor plate according to examples of the disclosure. Conductive plate  976  can be disposed on or included in substrate  972 . Conductive plate  976  can include any conductive material, including, but not limited to, gold (Au) and aluminum (Al). Conductive plate  976  can be any shape or size as long it is electrically insulated from the portions of the contacts carrying an electrical signal. For example, conductive plate  976  can be electrically insulated from contacts (e.g., contact  930  and contact  932 ) coupled to the integrated circuit and the contact configured to electrically charge the body (e.g., contact  931  or contact  933 ). In some examples, conductive plate  976  can include a plurality of conductive structures, where each conductive structure can be independently associated with a detector pixel in the detector array. In some examples, conductive plate  976  can be coupled to a voltage or current source (not shown). The voltage or current source can electrically charge conductive plate  976 . 
     Substrate  972  can further include an insulating post  948 . Insulting post  948  can include any material capable of electrically insulating conductive plate  976  and the body. Exemplary materials for insulating post  948  can include, but are not limited to, Silicon Dioxide (SiO 2 ) and Silicon Nitride (Si 3 N 4 ). In some examples, the body can include a conductive material, such as gold or aluminum, facing conductive plate  976  and insulating post  948 . In some examples, the conductive material on the body can be disposed on a side of sensor  920  opposite incident light. In some examples, sensor  920  can be disposed on a silicon substrate that is doped and conductive. 
     As discussed above, the body, which can include sensor  920  and the structures or legs  980 , can be coupled to a voltage source, and conductive plate  976  can be coupled to another voltage source. A voltage difference can be applied across the body and conductive plate  976  such that an electrostatic attraction causes the gap between the body and insulating post  948  to decrease. In some examples, the voltage difference can be applied such that the electrostatic attraction causes the body and insulating post  948  to come into contact. Although the body and insulating post  948  can be touching or in contact, insulating post  948  can be configured with a height to prevent the body and conductive plate  976  from shorting. In some examples, insulating post  948  can be used to eliminate thermal runaway by acting as a heat sink to dissipate the heat from light absorbers  910 . 
     The electrostatic attraction can vary with the applied voltage difference to change the pressure of the body against insulating post  948 . The pressure of the body against insulating post  948  can be related to the thermal conductance of detector pixel  900 . For example, a higher voltage difference can lead to a higher electrostatic attraction between the body and conductive plate  976 . The higher electrostatic attraction can lead to a higher pressure or more contact of the body against insulating post  948 . Higher pressure can lead to a higher thermal mass and therefore, a higher thermal conductance. As discussed above, a higher thermal conductance can lead to a decrease in sensitivity and a faster response time. 
     Conversely, a lower voltage difference applied between the body (e.g., the voltage applied to contact  931  coupled to the body and configured to electrically charge the body) and conductive plate  976  can lead to a lower electrostatic attraction between the body and conductive plate  976 . The lower electrostatic attraction can lead to a lower pressure or less contact between the body and insulating post  948 . Lower pressure can lead to a lower thermal mass, and therefore, a lower thermal conductance. Because of the lower thermal conductance, detector pixel  900  can have an increased sensitivity and a slower response time. 
     Optimization of detector pixel  900  for a given application can exploit the capabilities of a wide dynamic range that detector pixel  900  can offer. As discussed above, an image or a scene can include both bright (e.g., high photon flux) objects of interest and dim (e.g. low photon flux) objects. For the bright objects, detector pixel  900  can apply a large voltage difference between the body and conductive plate  976  to achieve a higher thermal conductance. While there may be a compromise in the sensitivity (e.g., lower sensitivity), the higher thermal conductance can outweigh the compromise by allowing detector pixel  900  to have a faster response time due to the higher dissipation of the heat generated in light absorbers  910 . For the dim objects, detector pixel  900  can apply a small voltage difference between the body and conductive plate  976  to achieve a higher sensitivity (and lower thermal conductance). Although there may be a compromise in the response time (e.g., slower response time), the capability of higher sensitivity for detecting low flux light may be more advantageous because the low flux light may otherwise not be detected if the sensitivity is too low. 
     Conductive plate  976 , legs  980 , and sensor  920  can be included in any of the above disclosed detectors.  FIGS. 9C-9E  illustrate top, plan, and cross-sectional views of an exemplary detector capable of electrostatically tuning for one or more flux levels according to examples of the disclosure. In some examples, the same object can reflect or transmit bright light (e.g., high flux light) at some wavelengths, but dim light (e.g., low flux light) at other wavelengths. Detector pixel  900  can be capable of adjusting the thermal conductance, and therefore, can shift the dynamic range for a given wavelength. To detect the low flux light, detector pixel  900  can be configured for a slower response time, higher sensitivity, and a low thermal conductance. At other wavelengths, the object can have a high absorbance relative to a reference, and incident light on light absorbers  910  can be high flux light. The high flux light can lead to a large signal, so detector pixel  900  can be configured for a faster response time and a high thermal conductance. Without the capability of varying the response time or sensitivity, a detector may only be capable of operating at wavelengths with high flux light (e.g., around 2.2 μm) or at wavelengths with low flux light (e.g., around 1.9 μm), but not both which would limit the capabilities of the system and the measurement accuracy. 
     Although  FIGS. 9A-9E  illustrate sensor  920  coupled to four structures or legs  980 , examples of the disclosure can include any number of structures or legs  980 . For example, sensor  920  can include three structures or legs  980  coupled to three contacts. Two of the contacts (e.g., contact  930  and contact  931 ) can be coupled to an integrated circuit and a third contact (e.g., contact  932 ) can be coupled to a voltage or current source to electrically charge the body. In some examples, a fourth leg can be excluded or not utilized for mechanical support so that sensor  920  can tilt a small degree when electrostatically attracted to conductive plate  976 . The small degree of tilt can be used to achieve a higher level of granularity in the contact pressure of sensor  920  (or body) against conductive plate  976 . For example, the small degree of tilt can be 0.5-1°. 
     In some examples, due to the small size of the detector pixels in a detector array, two adjacent detector pixels can be sampling the same area of a scene. Instead of having redundant signal values from the two adjacent detector pixels sampling the same area of a scene, the detector can achieve a wide dynamic range by intermixing detector pixels with different time constants.  FIG. 10  illustrates a plan view of a portion of an exemplary detector illustrating a plurality of detector pixels with intermixed time constants according to examples of the disclosure. Imager  1090  can include a plurality of detector pixels, such as detector pixel  1002 , detector pixel  1004 , detector pixel  1006 , and detector pixel  1008 . Each detector pixel can be coupled to a different light absorber through a post. Each detector pixel can include a sensor disposed on substrate  1072 . Sensor  1020  can be included in detector pixel  1002 , sensor  1022  can be included in detector pixel  1004 , sensor  1024  can be included in detector pixel  1006 , and sensor  1026  can be included in detector pixel  1008 . Sensor  1020 , sensor  1022 , sensor  1024 , and sensor  1026  can be any type of sensor, such as a thermistor or resistor, capable of measuring a change in temperature. 
     Substrate  1072  can include a plurality of contacts. Contact  1030  and contact  1031  can be included in detector pixel  1002  and can be coupled to sensor  1020 . Contact  1032  and contact  1033  can be included detector pixel  1004  and can be coupled to sensor  1022 . Contact  1034  and contact  1035  can be included in detector pixel  1006  and can be coupled to sensor  1024 . Contact  1036  and contact  1037  can be included in detector pixel  1008  and can be coupled to sensor  1026 . The contacts can be configured to couple the corresponding sensor to a unit cell in an integrated circuit. The integrated circuit can be coupled to a processor or controller. In some examples, the processor can bias each detector pixel of the detector array with a constant current or constant voltage and can measure the change in resistance due to light impinging on the corresponding light absorber. In some examples, at least two contacts can be coupled to a common voltage, such as Vdetcom. In some examples, at least two contacts can be coupled to the same biasing voltage source. In some examples, at least two sets of contacts can be coupled to the same circuitry or unit cell on the integrated circuit (e.g., ROIC). 
     Sensor  1020  of detector pixel  1002  can be coupled to contact  1030  and contact  1031  through structures or legs  1080 . Similarly, sensor  1026  of detector pixel  1008  can be coupled to contact  1036  and contact  1037  through structures or legs  1080 . Structures or legs  1080  can be any electrically conductive material capable of supporting sensor  1020  or sensor  1026 . In some examples, structures or legs  1080  can be electrically conductive. In some examples, structures or legs  1080  can be conductive spring structures or legs. In some examples, structures or legs  1080  included in detector pixel  1002  can have the same electrical properties to structures or legs  1080  included in detector pixel  1008 . One skilled in the art would appreciate that the same electrical properties can include tolerances that result in a 15% deviation. 
     Sensor  1022  of detector pixel  1004  can be coupled to contact  1032  and contact  1033  through structures or legs  1082 . Similarly, sensor  1024  of detector pixel  1006  can be coupled to contact  1034  and contact  1035  through structures or legs  1082 . Structures or legs  1082  can be any electrically conductive material capable of supporting sensor  1022  or sensor  1024 . In some examples, structures or legs  1082  can be electrically conductive. In some examples, structures or legs  1082  can be conductive spring structures or legs. In some examples, structures or legs  1082  included in detector pixel  1004  can have the same electrical properties as structures or legs  1082  included in detector pixel  1004 . In some examples, the total length of structures or legs  1080  can be greater than the total length of structures or legs  1082 . Because of having a longer length, detector pixels (e.g., detector pixel  1002  and detector pixel  1008 ) including structures or legs  1080  can have a slow time constant. Additionally, as a result of a shorter length, detector pixels (e.g., detector pixel  1004  and detector pixel  1006 ) including structures or legs  1082  can have a faster time constant. In some examples, structures or legs  1080  and  1082  can have other different properties, such as resistance or thermal conductivity, which can create a difference in time constant. 
     The arrangement of the detector array can be such that the time constant of the detector pixels can alternate between a fast time constant using structures or legs, such as structures or legs  1082 , having a shorter length and a slow time constant using structures or legs, such as structures or legs  1080 , having a longer length. Detector pixels (e.g., detector pixel  1004  and detector pixel  1006 ) with a fast time constant and detector pixels (e.g., detector pixel  1002  and detector pixel  1008 ) with a slow time constant can absorb incident light of the same wavelength, but the response can be different due to the differences in the understructure (e.g., the length of the structures or legs). In some examples, the alternating detector pixel types can form a checkerboard-type pattern. By alternating between detector pixels with a fast time constant and detector pixels with a slow time constant, imager  1090  can have a wide dynamic range because adjacent detector pixels, which can share the same image information (i.e., adjacent detector pixels can sample the same area of the scene), can have the capability of both fast time constant, high flux light detection and slow time constant, low flux light detection. 
     Although imager  1090  can be coupled to a conventional ROIC or the one illustrated in  FIG. 5 , the response of the sensor system can be limited by the frame rate of the ROIC. The frame rate can be the frequency or speed that the integrated charge or voltage can be sampled and read out to processor  562 . ROIC  500  can have a single frame rate where each row select line  544  and each column select line  546  can be activated at the same speed. As a result, the detector pixels in imager  1090  with fast time constant can be limited by the frame rate of the ROIC, which can negate any benefits of having a detector array with intermixed time constants. 
       FIG. 11A  illustrates an exemplary ROIC capable of multiple frame rates according to examples of the disclosure. ROIC  1100  can comprise a plurality of unit cells  1110  and a plurality of unit cells  1112 . Each unit cell  1110  and unit cell  1112  in ROIC  1100  can be coupled to a detector pixel  1130  or detector pixel  1134 , respectively, included in a detector array. Unit cell  1110  can convert a photocurrent generated by each detector pixel  1130  (coupled to Vdetcom  1140 ) to a voltage indicative of the properties of detected light. Unit cell  1112  can convert a photocurrent generated by each detector pixel  1134  (coupled to Vdetcom  1140 ) to a voltage indicative of the properties of detected light. 
     Unit cell  1110  and unit cell  1112  can comprise an integrator, a preamplifier, a SH circuit, and an ADC  1132 . In some examples, the current from detector pixel  1130  (or detector pixel  1134 ) can be weak or small, incremental current. One way to generate a large measurable output from the small, incremental current can be to integrate the photocurrent using an integrating capacitor C int    1120 . Integrating capacitor  1120  can be coupled to a detector pixel  1130  (or detector pixel  1134 ) in the detector array. Integrating capacitor C int    1120  can be configured to store charge associated with light detected by the corresponding detector pixel  1130  (or detector pixel  1134 ). Integrating capacitor C int    1120  can be coupled to an amplifier  1160 . An integration time can be set to determine the fixed period of time when the photocurrent from detector pixel  1130  (or detector pixel  1134 ) can be integrated. At the end of the integration time, C int  can be proportional to the current, and should represent incident light on detector pixel  1130  (or detector pixel  1134 ). A reset transistor  1150  can be coupled to the integrating capacitor C int    1120  to discharge the capacitor. At the end of the integration time, the integrated voltage can be sampled and held on a hold capacitor C SH    1122  through transistor SH  1152 . The hold capacitor C SH    1122  can be configured to store the integrated charge. 
     ROIC  1100  can include two independent image state machines. Unit cells  1110  can be coupled to row select lines  1144 , whereas unit cells  1112  can be coupled to row select lines  1145 . Unit cells  1112  can be coupled to column select lines  1146 , whereas unit cells  1112  can be coupled to column select lines  1147 . Row select lines  1144  and column select lines  1146  coupled to unit cells  1110  can be activated (i.e., the integrated charge from unit cells  1110  can be sampled) at a first frame rate. Row select lines  1145  and column select lines  1147  coupled to unit cells  1112  can be activated (i.e., the integrated charge from unit cells  1112  can be sampled) at a second frame rate. In some examples, the first frame rate can be different from the second frame rate. In some examples, the second frame rate can be equal to (or within 10% from) a multiple of the first frame rate, where the multiple can be equal to (or within 10% from) the ratio of the thermal conductivities of the structures or legs of the corresponding adjacent detector pixels. For example, unit cell  1110  can be coupled to detector pixel  1004  of imager  1090 , and unit cell  1112  can be coupled to detector pixel  1002  of imager  1090 . Detector pixel  1004  can have a thermal conductance that is ten times greater than the thermal conductance of detector pixel  1002  due to structures or legs  1082  having a higher thermal conductance and longer length than structures or legs  1080 . The second frame rate can be 60 Hz, and due to the ten times greater thermal conductance, the first frame rate can be 600 Hz. As a result, the response of the two different detector pixels (e.g., detector pixel  1002  and detector pixel  1004 ) can differ by the same multiple (e.g., 10×). 
     ROIC  1100  can further include a plurality of multiplexers. Unit cells  1110  can be coupled to a multiplexer  1190 , and unit cells  1112  can be coupled to a multiplexer  1192 .  FIG. 11B  illustrates an exemplary ROIC capable of multiple frame rates with unit cells arranged in a checkboard-pattern according to examples of the disclosure. ROIC  1100  can be arranged such that unit cells  1110  and unit cells  1112  are interleaved in an alternating pattern (i.e., checkerboard-pattern). As illustrated, unit cells  1110  can be coupled to column amplifier  1135  and multiplexer  1190 , and unit cells  1112  can be coupled to column amplifier  1133  and multiplexer  1192 . 
     Although  FIGS. 11A-11B  illustrate two independent image state machines, two sets of row select lines (e.g., row select lines  1144  and row select lines  1145 ), two sets of column select lines (e.g., column select lines  1146  and column select lines  1147 ), two multiplexers (e.g., multiplexer  1190  and multiplexer  1192 ), and two different frame rates (e.g., 60 Hz and 600 Hz), examples of the disclosure are not limited to two, but can include any number of state machines, sets of row select lines, sets of column select lines, multiplexers, and frame rates. Furthermore, although  FIGS. 11A-11B  illustrate ROIC  1100  arranged in a checkerboard-pattern, examples of the disclosure can include any arrangement suitable for incorporating multiple frame rates. 
     As discussed above, the photocurrent from a detector can be integrated using an integrating capacitor (e.g., integrating capacitor Cint  520  in  FIG. 5  or integrating capacitor  1120  in  FIG. 11A ). The integrating capacitor can store charge related to both the photocurrent and the dark current. The dark current can be leakage current generated in response to the bias voltage applied to the detector. The dark current can be based on several factors such as the bandgap of the material, the quality of the material growth, and the size of the active area of the detector. A larger dark current can lead to a lower SNR and a higher output current stored in the integrating capacitor. In some examples, the dark current can saturate the integrating capacitor. 
     Saturation of the integrating capacitor due to dark current can be prevented by lower the temperature or actively cooling the detector, for example. In general, the dark current can increase when the temperature of the detector increases. However, actively cooling the detector may not be feasible for certain applications. Active cooling can require higher power consumption and result in a larger and heavier device, which may not be suitable for portable electronic devices, for example. Furthermore, in some examples, active cooling may not be sufficient to lower the dark current to prevent saturation of the integrating capacitor. 
     To prevent saturation of the integrating capacitor, the frame rate of the ROIC can be increased. When an integrating capacitor is sampled or read out, the capacitor can be reset or discharged, thereby preventing residual charge that can increase the likelihood of saturation. In some examples, the frame rate can be determined based on a specific readout time. In some examples, the frame rate can be based on the capacitance of the integrating capacitor. In some examples, the frame rate can be based on the intended application and/or properties of the object being measured. In some examples, the frame rate can be based on the dark current, the active area of the detector, or both. In some examples, the frame rate can be based on the optical flux. 
     When the optical flux increases, the frame rate can increase. For example, in applications including active illumination (i.e., illumination of the measured object or the active area of the detector by a light source), the saturation may need to be higher to account for optical flux and higher photocurrents. Active illumination can be advantageous due to the lower amount of unwanted variations in the output current due to ambient light levels and inherent reflection of objects in the background (i.e., objects distinct from the object of interest). The unwanted variations can make it difficult to generate reproducible results and to account for differences in environmental conditions. Furthermore, active illumination can lead to a higher ratio of photocurrent to dark current, and thus, a higher SNR. In some examples, active illumination can lead to a photocurrent that is 2-10 times greater than the dark current. In some examples, the active illumination source can be configured to emit 100 nW per detector pixel. In some examples, the frame rate can be greater than 60 Hz. In some examples, the frame rate can be between 1 kHz and 10 kHz, which can be useful for applications such as spectroscopy. 
     Furthermore, saturation of the integrating capacitor can be prevented by employing a larger integrating capacitor. The capacitance of the integrating capacitor can depend on many factors such as the frame rate and the active area of the detector. For higher frame rates, the integrating capacitor can be discharged more frequently. As a result, for the same saturation level, the capacitance of the integrating capacitor can be smaller. For example, a 100 mega electron integrating capacitor can be used with a 1 kHz frame rate or a 10 mega electron integrating capacitor can be used with a 10 kHz frame rate. For detector pixels with a larger active area, the capacitance of the integrating capacitor can be increased. For example, a 10 mega electron integrating capacitor can be used for a 15 μm detector pixel size or smaller or a 100 mega electron integrating capacitor can be used for a 15-20 μm detector pixel size. In some examples, the capacitance of the integrating capacitor can be determined based on the speed of the ADC. In some examples, the capacitance of the integrating capacitor can be based on the source optical flux. For a higher source optical flux, the capacitance of the integrating capacitor can be larger. 
     In some examples, the capacitance of the integrating capacitor can be based on the active area of the detector divided by the frame rate. For example, a 400 mega electron integrating capacitor can be used for a 30 μm detector pixel size operating at a frame rate of 100 kHz, and a 40 mega electron integrating capacitor can be used for the same size detector pixel when operating at a frame rate of 10 kHz. 
       FIG. 12  illustrates an exemplary process flow for adjusting one or more parameters of the ROIC to prevent saturation of the integrated capacitors according to examples of the disclosure. Process  1200  can begin with biasing one or more detector pixels (step  1202 ). A controller or user can set a frame rate for sampling and reading one or more integrated capacitors (step  1204 ). In some examples, the frame rate can be a predetermined value. The controller or user can active the illumination source (step  1206 ). In some examples, the controller or user can activate the illumination source only after determining that the power consumption of the device is below another predetermined value, for example. The controller or user can determined if the output current is saturating one or more integrating capacitors, is greater than a predetermined level, a higher contrast is desired, or any combination therefore (step  1208 ). If so, the controller or user can determine if the frame rate is within an acceptable range (step  1210 ). If the frame rate is within an acceptable range, the frame rate can be changed (step  1212 ). For example, the frame rate can be increased to increase the sensitivity without saturating the integrating capacitors. In some examples, the acceptable range can be based on the application. If the frame rate is not within an acceptable range, the bias applied to the detector can be changed (step  1214 ). In some examples, the controller can determine if the detector is background-limited in performance (BLIP) limited and can adjust the frame rate if not. In some examples, the controller can determine that the output current is not saturating one or more integrating capacitors (or is less than or equal to a first predetermined level), while also below a second predetermined level (e.g., a level sufficient to ascertain the photocurrent) (step  1216 ). If the output current is below the first predetermined level, the power of the illumination source can be adjusted (step  1218 ). In this manner, the system can dynamically change the frame rate, power of the illumination source, and detector bias to account for variations in optical flux (due to the properties of the measured object, for example), environmental conditions, and desired detector performance (e.g., sensitivity). 
     One or more of the functions described above can be performed, for example, by firmware stored in memory and executed by a processor or controller. The firmware can also be stored and/or transported within any non-transitory computer-readable storage medium for use by or in connection with an instruction execution system, apparatus, or device, such as a computer-based system, processor-containing system, or other system that can fetch the instructions from the instruction execution system, apparatus, or device and execute the instructions. In the context of this document, a “non-transitory computer-readable storage medium” can be any medium (excluding a signal) that can contain or store the program for use by or in connection with the instruction execution system, apparatus, or device. The non-transitory computer readable storage medium can include, but is not limited to, an electronic, magnetic, optical, electromagnetic, infrared, or semiconductor system, apparatus, or device, a portable computer diskette (magnetic), a random access memory (RAM) (magnetic), a read-only memory (ROM) (magnetic), an erasable programmable read-only memory (EPROM) (magnetic), a portable optical disc such as a CD, CD-R, CD-RW, DVD, DVD-R, or DVD-RW, or flash memory such as compact flash cards, secured digital cards, USB memory devices, memory sticks and the like. In the context of this document, a “transport medium” can be any medium that can communicate, propagate, or transport the program for use by or in connection with the instruction execution system, apparatus, or device. The transport readable medium can include, but is not limited to, an electronic, magnetic, optical, electromagnetic, or infrared wired or wireless propagation medium. 
     A light detector is disclosed. The light detector can comprise: a first light absorber configured to absorb one or more first wavelengths of light and including at least one of a plurality of slits, a mesh, and a plate absorber; a first temperature sensor thermally coupled to the first light absorber; and a second light absorber configured to absorb one or more second wavelengths of light. Additionally or alternatively to one or more examples disclosed above, in some examples, the first light absorber includes a plurality of slits oriented in a first polarizing direction, and the second light absorber includes a plurality of slits oriented in a second polarizing direction different from the first polarizing direction. Additionally or alternatively to one or more examples disclosed above, in some examples, the second polarizing direction is orthogonal to the first polarizing direction. Additionally or alternatively to one or more examples disclosed above, in some examples, the light detector further comprises: a third light absorber including a plurality of slits oriented in a third polarizing direction orthogonal to the first polarizing direction; a third temperature sensor thermally coupled to the third light absorber; a fourth light absorber including a plurality of slits oriented in a fourth polarizing direction orthogonal to the second polarizing direction; and a fourth temperature sensor thermally coupled to the fourth light absorber. Additionally or alternatively to one or more examples disclosed above, in some examples, the light detector further comprises: a second temperature sensor thermally coupled to the second light absorber, wherein the first and second temperature sensors are electrically coupled, and the light detector is capable of determining an angle of polarization of light absorbed by the first and second light absorbers based on a differential reading between the first and second temperature sensors. Additionally or alternatively to one or more examples disclosed above, in some examples, the first light absorber includes a plurality of embedded slits or polarizer lines. Additionally or alternatively to one or more examples disclosed above, in some examples, the plurality of slits of the first light absorber are spaced a first distance apart, the first distance equal to a quarter of at least one of the one or more first wavelengths of light. Additionally or alternatively to one or more examples disclosed above, in some examples, a length of an outer edge of the first light absorber is equal to a long-end wavelength of the one or more first wavelengths of light. Additionally or alternatively to one or more examples disclosed above, in some examples, a distance between adjacent slits included in the plurality of slits of the first light absorber is equal to a short-end wavelength of the one or more first wavelengths of light. Additionally or alternatively to one or more examples disclosed above, in some examples, the second light absorber includes a second post to thermally couple to the first temperature sensor, the detector further comprising: a third light absorber configured to absorb light, wherein the third light absorber includes a third post to thermally couple to the first temperature sensor; and a fourth light absorber configured to absorb light, wherein the fourth light absorber includes a fourth post to thermally couple to the first temperature sensor. Additionally or alternatively to one or more examples disclosed above, in some examples, the light detector further comprises: an encapsulation disposed on at least a portion of the first light absorbers and including a transparent material. Additionally or alternatively to one or more examples disclosed above, in some examples, the light detector further comprises: an encapsulation supporting at least the first and second light absorbers. Additionally or alternatively to one or more examples disclosed above, in some examples, the light detector further comprises: a second temperature sensor thermally coupled to the second light absorber; and a processor capable of calculating an angle of polarization of light absorbed by the first and second light absorbers based on at least information from the first and second temperature sensors. Additionally or alternatively to one or more examples disclosed above, in some examples, the light detector further comprises: a reflector having a surface facing at least one of the first and second light absorbers and spaced a distance equal to a quarter of at least one of the one or more first wavelengths of light or at least one of the one or more second wavelengths of light. Additionally or alternatively to one or more examples disclosed above, in some examples, the light detector further comprises: a second temperature sensor thermally coupled to the second light absorber, wherein the reflector is thermally coupled to at least one of the first and second temperature sensors. Additionally or alternatively to one or more examples disclosed above, in some examples, the light detector further comprises: one or more structures configured to support the reflector; and an encapsulation, the encapsulation comprising a same material as the one or more structures. Additionally or alternatively to one or more examples disclosed above, in some examples, the light detector further comprises: a first electrical insulator thermally coupled to the first light absorber and the first temperature sensor, wherein the first electrical insulator electrically isolates the first light absorber from the second light absorber, and further wherein the first temperature sensor thermally couples the first light absorber to the second light absorber. Additionally or alternatively to one or more examples disclosed above, in some examples, the first and second light absorbers are included in a plurality of light absorbers, each light absorber is a mesh, and the plurality of light absorbers form a capacitive resonant mesh. Additionally or alternatively to one or more examples disclosed above, in some examples, the mesh of the first light absorber includes a plurality of wires spaced a first distance apart, the first distance equal to a quarter of at least one of the one or more first wavelengths of light. Additionally or alternatively to one or more examples disclosed above, in some examples, the plurality of slits of the first light absorber at least partially overlaps the plurality of slits of the second light absorber. Additionally or alternatively to one or more examples disclosed above, in some examples, the one or more first wavelengths of light includes at least one of the one or more second wavelengths of light, and further wherein the first light absorber is spaced a second distance from the second light absorber, the second distance equal to a quarter of the at least one of the one or more second wavelengths of light to be absorbed by the first and second light absorbers. Additionally or alternatively to one or more examples disclosed above, in some examples, the light detector further comprises: a first post thermally coupled to the first light absorber and first temperature sensor, wherein the first post passes through the second light absorber while remaining thermally isolated from the second light absorber. Additionally or alternatively to one or more examples disclosed above, in some examples, the light detector further comprises: a second temperature sensor thermally coupled to the second light absorber, and a second post, wherein the first post is located at a first position of the first light absorber, and the second post is located at a second position of the first light absorber, and further wherein the first position and the second position are symmetric with respect to a center position of the first light absorber. Additionally or alternatively to one or more examples disclosed above, in some examples, the first light absorber overlaps the second light absorber, and further wherein at least one of the one or more first wavelengths of light is longer than at least one of the one or more second wavelengths of light. Additionally or alternatively to one or more examples disclosed above, in some examples, at least one of the one or more first wavelengths of light and the one or more second wavelengths of light includes short-wavelength infrared (SWIR), and further wherein the light detector is configured to be uncooled. Additionally or alternatively to one or more examples disclosed above, in some examples, a size of the first light absorber differs from a size of the second light absorber. 
     A method of detecting incident radiation is disclosed. The method can comprise: applying a first voltage to a first light absorber included in a detector; applying a second voltage to a second light absorber included in the detector; measuring a first photocurrent from the first light absorber, the first photocurrent associated with one or more first wavelengths of light; measuring a second photocurrent from the second light absorber, the second photocurrent associated with one or more second wavelengths of light; and determining a polarization of the incident radiation based on the measured first and second photocurrents. Additionally or alternatively to one or more examples disclosed above, in some examples, the second photocurrent is included in the first photocurrent, and further wherein the measuring the first photocurrent and measuring the second photocurrent includes determining a different reading between the first light absorber and the second light absorber. 
     An uncooled light detection system is disclosed. The detection system can comprise: a detector pixel configured to detect incident light; an illumination source configured to emit light; and a readout circuit including one or more integrating capacitors, wherein each integrating capacitor has a predetermined capacitance, and the readout circuit is configured to operate at a frame rate determined such that the product of the predetermined capacitance and the frame rate is proportional to an active area of the detector pixel. Additionally or alternatively to one or more examples disclosed above, in some examples, the product of the predetermined capacitance and the framerate is proportional to a dark current value obtained from the readout circuit. Additionally or alternatively to one or more examples disclosed above, in some examples, the predetermined capacitance is between 10-200 mega electrons. Additionally or alternatively to one or more examples disclosed above, in some examples, the frame rate is between 1-10 kHz. Additionally or alternatively to one or more examples disclosed above, in some examples, a target wavelength of light to be absorbed by the detector pixel is greater than 1.7 microns. Additionally or alternatively to one or more examples disclosed above, in some examples, the detection system is configured to operate at a temperature above 15 degrees Celsius. Additionally or alternatively to one or more examples disclosed above, in some examples, a power level of the illumination source is dynamically set such that a photocurrent measured by the readout circuit is greater than a dark current value obtained from the readout circuit. Additionally or alternatively to one or more examples disclosed above, in some examples, the power level of the illumination source is dynamically set such that the photocurrent measured by the readout circuit is 2-10 times the dark current value obtained from the readout circuit. Additionally or alternatively to one or more examples disclosed above, in some examples, the uncooled light detection system further comprises an array of detector pixels including the detector pixel, wherein the array of detector pixels is incorporated in an imager. 
     A method of operating a light detection system, the light detection system including one or more detector pixels and a readout circuit is disclosed. The method can comprise: applying a bias to the one or more detector pixels; setting a frame rate of the readout circuit; sampling an integrating capacitor included in the readout circuit to obtain an output current; determining whether the integrating capacitor is saturated based on the output current; and increasing the frame rate of the readout circuit in response to determining that the integrating capacitor is saturated. Additionally or alternatively to one or more examples disclosed above, in some examples, the light detection system further includes an illumination source, and the method further comprising: determining whether a photocurrent included in the output current is greater than a predetermined threshold; and increasing a power of the illumination source in response when the output current is less than or equal to the predetermined threshold. Additionally or alternatively to one or more examples disclosed above, in some examples, the method further comprises: determining whether an updated frame rate is within a predetermined ranged; increasing the frame rate to the updated frame rate when the updated frame rate is within the predetermined range; and adjusting the bias applied to the one or more detector pixels when the updated frame rate is outside the predetermined range. 
     An integrated circuit configured for measuring a plurality of photocurrents from a detector array is disclosed. The method can comprise: a first set of select lines and a second set of select lines; a first set of unit cells coupled to the first set of select lines and configured to operate at a first frame rate; a second set of unit cells coupled to the second set of select lines and configured to operate at a second frame rate, wherein the first set of units cells are interleaved with the second set of unit cells; and a first multiplexer coupled to the first set of unit cells and a second multiplexer coupled to the second set of unit cells, wherein the first frame rate is different from the second frame rate. Additionally or alternatively to one or more examples disclosed above, in some examples, the first set of unit cells are coupled to a first set of amplifiers having a first gain and the second set of unit cells are coupled to a second set of amplifiers having a second gain, and further wherein the first gain is different from the second gain. 
     An imager is disclosed. The imager can comprise: a first set of detector pixels, each detector pixel in the first set including: one or more first light absorbers, each first light absorber configured for absorbing light and producing heat in response to the absorbed light, a first sensor thermally coupled to the one or more first light absorbers and configured for detecting a temperature change in the one or more first light absorbers due to the absorbed light, and a plurality of first structures having a first characteristic and coupled to the first sensor and a plurality of first contacts; and a second set of detector pixels, each detector pixel in the second set including: one or more second light absorbers, each second light absorber configured for absorbing light and producing heat in response to the absorbed light, a second sensor thermally coupled to the one or more second light absorbers and configured for detecting a temperature change in the one or more second light absorbers due to the absorbed light, and a plurality of second structures having a second characteristic and coupled to the second sensor and a plurality of second contacts, wherein the first characteristic and second characteristic include one or more lengths, time constants, resistances, or thermal conductivities that are different. Additionally or alternatively to one or more examples disclosed above, in some examples, the first set of detector pixels are interleaved with the second set of detector pixels. Additionally or alternatively to one or more examples disclosed above, in some examples, the plurality of first structures has a length longer than the plurality of second structures, and further wherein the one or more first light absorbers has a slower time constant than the one or more second light absorbers. 
     A method of integrating a plurality of photocurrents is disclosed. The method can comprise: sampling a first set of voltage values stored in a first set of capacitors; transmitting the first set of voltage values to a first multiplexer; sampling a second set of voltage values stored in a second set of capacitors; transmitting the second set of voltage values to a second multiplexer; reading the first set of voltage values from the first multiplexer at a first frame rate; reading the second set of voltage values from the second multiplexer at a second frame rate, wherein the first frame rate is different from the second frame rate. Additionally or alternatively to one or more examples disclosed above, in some examples, the first set of voltage values are associated with a first set of detector pixels and the second set of voltage values are associated with a second set of detector pixels, and further wherein a ratio of the second frame rate to the first frame rate is equal to a ratio of a thermal conductivity of the first set of detector pixels and a thermal conductivity of the second set of detector pixels. Additionally or alternatively to one or more examples disclosed above, in some examples, the method further comprises: setting the first frame; and setting the second frame rate such that the first frame rate is equal to a multiple of the second frame rate. 
     A detector pixel is disclosed. The detector pixel can comprise: a first light absorber configured for absorbing a first light and producing heat in response to the first light; a second light absorber configured for absorbing a second light and producing heat in response to the second light; a first sensor thermally coupled to the first light absorber and configured for detecting a first temperature change in the first light absorber due to the absorbed first light; and a plurality of first contacts electrically coupled to the first sensor and a circuit, wherein the circuit is further coupled to the second light absorber. Additionally or alternatively to one or more examples disclosed above, in some examples, the second light absorber is disposed on a substrate and is located closer to the substrate than the first light absorber. Additionally or alternatively to one or more examples disclosed above, in some examples, the first light absorber overlaps at least a portion of the second light absorber, the first light being incident on the first light absorber and including a first portion and a second portion, the first portion absorbed by the first light absorber and the second portion not absorbed by the first light absorber, and wherein the second light absorber absorbs the second portion of the first light. Additionally or alternatively to one or more examples disclosed above, in some examples, the detector pixel further comprises: a second sensor thermally coupled to the second light absorber and configured for detecting a second temperature change in the second light absorber due to the absorbed second light; and one or more second contacts electrically coupled to the second sensor and the integrated circuit. Additionally or alternatively to one or more examples disclosed above, in some examples, the first sensor is thermally coupled to the second light absorber and configured for detecting a second temperature change due to the absorbed second light. Additionally or alternatively to one or more examples disclosed above, in some examples, an absorbance of the first light absorber is greater than an absorbance of the second light absorber. Additionally or alternatively to one or more examples disclosed above, in some examples, a sensitivity of the first light absorber is less than a sensitivity of the second light absorber. Additionally or alternatively to one or more examples disclosed above, in some examples, the second light absorber is configured for absorbing the second light only when a flux of the first light and second light is greater than a threshold value. Additionally or alternatively to one or more examples disclosed above, in some examples, the first light and second light are different, and the first light absorber and second light absorber are non-overlapping. Additionally or alternatively to one or more examples disclosed above, in some examples, the first light absorber and second light absorber are different sizes. Additionally or alternatively to one or more examples disclosed above, in some examples, the detector pixel further comprises: a third light absorber configured for absorbing a third light and producing heat in response to the third light; a third sensor thermally coupled to the third light absorber and configured for detecting a third temperature change in the third light absorber due to the absorbed third light; and one or more third contacts electrically coupled to the third sensor and the integrated circuit. Additionally or alternatively to one or more examples disclosed above, in some examples, an incident light includes the first light and the second light, and further wherein the third light absorber is located closer to the incident light than at least one of the first light absorber and the second light absorber. Additionally or alternatively to one or more examples disclosed above, in some examples, the third light absorber has at least one of a different size, form factor, heat capacity, and type of material than at least one of the first light absorber and the second light absorber. Additionally or alternatively to one or more examples disclosed above, in some examples, an absorbance of the third light absorber is less than an absorbance of the first light absorber, second light absorber, or both. Additionally or alternatively to one or more examples disclosed above, in some examples, the detector pixel is incorporated into an imager configured for absorbing short-wave infrared wavelength light. Additionally or alternatively to one or more examples disclosed above, in some examples, the detector pixel further comprises: a thermal structure coupled to the first sensor and the plurality of first contacts; and a third light absorber configured for absorbing at least one of the first light and second light, the third light absorber thermally coupled to the thermal structure. Additionally or alternatively to one or more examples disclosed above, in some examples, the third light absorber includes a same material composition as the first light absorber and has a resistivity equal to 10% of a resistivity of the first light absorber. 
     A method of detecting incident radiation is disclosed. The method can comprise: receiving a first photocurrent from a first light absorber included in a detector pixel; receiving a second photocurrent from a second light absorber included in the detector pixel; determining whether the first photocurrent is indicative of a flux of incident light greater than or equal to a flux threshold value; and when the flux of incident light is greater than or equal to a flux threshold value, ignoring the first photocurrent and determining one or more properties of incident light based on the second photocurrent. Additionally or alternatively to one or more examples disclosed above, in some examples, the method further comprises: when the flux of incident light is less than the flux threshold value, determining one or more properties of incident light based on the first photocurrent. 
     A detector pixel is disclosed. The detector pixel can comprise: one or more light absorbers, each light absorber configured for absorbing light and producing heat in response to the absorbed light; one or more sensors thermally coupled to the one or more light absorbers and configured for detecting a temperature change in the one or more light absorbers due to the absorbed light; a plurality of contacts, each sensor of the one or more sensors coupled to at least two of the plurality of contacts; a plurality of conductive structures, each conductive structure coupled to one of the one or more sensors and one of the plurality of contacts; a first conductive plate coupled to at least one of the plurality of contacts and configured for receiving a first electrical charge from the at least one of the plurality of contacts, wherein at least one of the one or more sensors and first conductive plate are located on a first substrate; and a second conductive plate located on a second substrate and configured for receiving a second electrical charge, the second conductive plate including an insulator. Additionally or alternatively to one or more examples disclosed above, in some examples, the plurality of structures includes: a first structure and a second structure configured to electrically couple one of the one or more sensors to an integrated circuit, a third structure configured to electrically couple a voltage source to the first conductive plate, and a fourth structure configured to mechanically support one of the one or more sensors and prevent the one of the one or more sensors from tilting, turning, flipping, or a combination thereof. Additionally or alternatively to one or more examples disclosed above, in some examples, the detector pixel is incorporated into a sensor system, the sensor system including: a first voltage source coupled to at least one of the plurality of contacts and configured to apply a first voltage to the first conductive plate, and a second voltage source coupled to the second conductive plate and configured to apply a second voltage to the second conductive plate, wherein applying the first voltage and applying the second voltage creates a voltage difference across the first conductive plate and the second conductive plate such that the first and second conductive plates are electrostatically attracted to each other. Additionally or alternatively to one or more examples disclosed above, in some examples, the insulator included in the second conductive plate is configured as a heat sink to thermally conduct heat away from the one or more light absorbers. 
     A method of detecting incident radiation is disclosed. The method can comprise: applying a first voltage to a first conductive plate included in a detector element; applying a second voltage to a second conductive plate included in the detector element, wherein the second conductive plate includes an insulator, causing the first conductive plate to contact the insulator included in the second conductive plate by creating a difference between the applied first voltage and applied second voltage. Additionally or alternatively to one or more examples disclosed above, in some examples, the difference between the applied first voltage and applied second voltage is based on a flux of the incident radiation, thermal conductance of the detector element, or both. 
     Although the disclosed examples have been fully described with reference to the accompanying drawings, it is to be noted that various changes and modifications will become apparent to those skilled in the art. Such changes and modifications are to be understood as being included within the scope of the disclosed examples as defined by the appended claims.

Metadata:
Filing Date: 20160108
Publication Date: 20180410
Grant Date: 20180410
Priority Date: 20150109
Inventors: KANGAS MIIKKA M.
BISHOP MICHAEL J.
CHEN ROBERT
SIMON DAVID I.
Sontag, III Harold L.
SKIDMORE GEORGE DEE
Assignee: APPLE INC
CPC Classifications: [{"code": "G01J5/0225", "inventive": true, "first": false, "tree": "[]"}, {"code": "G01J2005/202", "inventive": false, "first": false, "tree": "[]"}, {"code": "G01J2005/202", "inventive": false, "first": false, "tree": "[]"}, {"code": "G01J5/20", "inventive": true, "first": false, "tree": "[]"}, {"code": "G01J5/0853", "inventive": true, "first": false, "tree": "[]"}, {"code": "G01J5/20", "inventive": true, "first": false, "tree": "[]"}, {"code": "G01J5/0853", "inventive": true, "first": false, "tree": "[]"}, {"code": "G01J5/0846", "inventive": true, "first": false, "tree": "[]"}, {"code": "G01J5/0225", "inventive": true, "first": true, "tree": "[]"}, {"code": "G01J4/04", "inventive": true, "first": false, "tree": "[]"}, {"code": "G01J5/0846", "inventive": true, "first": false, "tree": "[]"}, {"code": "G01J2005/202", "inventive": false, "first": false, "tree": "[]"}, {"code": "G01J5/20", "inventive": true, "first": false, "tree": "[]"}, {"code": "G01J5/0853", "inventive": true, "first": false, "tree": "[]"}, {"code": "G01J5/0846", "inventive": true, "first": false, "tree": "[]"}, {"code": "G01J5/0825", "inventive": true, "first": true, "tree": "[]"}, {"code": "G01J5/0853", "inventive": true, "first": false, "tree": "[]"}, {"code": "G01J2005/202", "inventive": false, "first": false, "tree": "[]"}, {"code": "G01J4/04", "inventive": true, "first": false, "tree": "[]"}, {"code": "G01J5/20", "inventive": true, "first": false, "tree": "[]"}, {"code": "G01J5/0846", "inventive": true, "first": false, "tree": "[]"}, {"code": "G01J5/59", "inventive": true, "first": false, "tree": "[]"}, {"code": "G01J5/59", "inventive": true, "first": false, "tree": "[]"}, {"code": "G01J5/59", "inventive": true, "first": true, "tree": "[]"}, {"code": "G01J5/0225", "inventive": true, "first": true, "tree": "[]"}]
Family ID: 55361940