Patent Description:
An optical sensor device may be utilized to capture information. For example, the optical sensor device may capture information relating to a set of electromagnetic frequencies. The optical sensor device may include a set of sensor elements (e.g., optical sensors, spectral sensors, and/or image sensors) that capture the information. For example, an array of sensor elements may be utilized to capture information relating to multiple frequencies. The sensor element array may be associated with an optical filter. The optical filter may include one or more channels that respectively pass particular frequencies to sensor elements of the sensor element array. Documents <CIT>, <CIT>, <CIT>, <CIT>, and <CIT> disclose multi-channel optical filtres.

In some implementations, an optical filter includes a first pair of mirrors; a second pair of mirrors, wherein the second pair of mirrors and the first pair of mirrors reflect different portions of an electromagnetic spectrum; and a common spacer positioned between the first pair of mirrors and between the second pair of mirrors.

In some implementations, a method of manufacturing an optical filter includes depositing, on a substrate, a first mirror, a second mirror, and a third mirror, wherein the first mirror, the second mirror, and the third mirror do not overlap each other; depositing, above the first mirror, the second mirror, and the third mirror, a common spacer; depositing, on the common spacer and opposite the first mirror, a fourth mirror, wherein the fourth mirror is paired with the first mirror to reflect a first portion of an electromagnetic spectrum; depositing, on the common spacer and opposite the second mirror, a fifth mirror, wherein the fifth mirror is paired with the second mirror to reflect a second portion of the electromagnetic spectrum; and depositing, on the common spacer and opposite the third mirror, a sixth mirror, wherein the sixth mirror is paired with the third mirror to reflect a third portion of the electromagnetic spectrum.

In some implementations, a method of manufacturing an optical filter includes depositing, on a substrate, a first mirror and a second mirror, wherein the first mirror and the second mirror do not overlap, wherein the first mirror is to reflect a set of first wavelengths of an electromagnetic spectrum, wherein the second mirror is to reflect a set of second wavelengths of the electromagnetic spectrum, and wherein second wavelengths of the set of second wavelengths are shifted with respect to first wavelengths of the set of first wavelengths; depositing, above the first mirror and the second mirror, a common spacer; and depositing, on the common spacer, opposite the first mirror, and opposite the second mirror, one or more additional mirrors.

An optical filter may use an interferometer, such as a Fabry-Perot interference filter, an etalon, and/or the like. An interferometer may pass light associated with a particular wavelength or wavelength range (that is in resonance with the interferometer) and may block other light. For example, the particular wavelength may be based on characteristics of the interferometer (e.g., a length of the interferometer, an optical path length of the interferometer, a reflectivity of surfaces of the interferometer, and/or the like). Some interferometers may include reflective surfaces, which are referred to herein as mirrors. Light may enter the interferometer and may reflect between the mirrors. Destructive interference may cause only the light associated with the particular wavelength to pass through the interferometer.

An optical device (e.g., comprising a spectrometer or one or more other optical sensors and/or spectral sensors) may use filtered light to perform a measurement associated with a particular wavelength. An interferometer or a set of interferometers may filter the light. In some cases, it may be beneficial to filter light to many different wavelengths, which may involve the use of many interferometers. However, the usage of many, different interferometers to measure wavelengths that are close to each other (e.g., in terms of filtered wavelengths) may present certain difficulties. For example, a resonant wavelength of the interferometer may be based on the optical path length in the interferometer (which may be a function of refractivity and length of the interferometer) and reflection characteristics of the mirrors of the interferometer. One way to vary the resonant wavelength, and thus the passed wavelength of light, is to change the length of the interferometer by varying a thickness of a spacer of the interferometer. However, generating many different interferometers on an optical filter with different spacer thicknesses may require many deposition runs (e.g., to deposit layers of the spacer), which increases cost and complexity of fabrication. Furthermore, if the optical device is to measure two wavelengths that are close to each other, then the difference between thicknesses of the corresponding spacers may be difficult or impossible to achieve, using deposition technology, due to challenges in thickness control.

Some implementations described herein provide an optical filter for which the passed wavelength is varied based on properties of mirrors of the optical filter and/or using shared spacers across multiple, different mirror designs. For example, some implementations described herein may consolidate spacer construction into a common deposition or a common set of depositions across multiple interferometers that have different mirror designs. By varying the different mirror designs, each mirror design may address a different wavelength region. Thus, filters can be generated that address multiple different wavelength regions using fewer coating runs than a filter in which wavelength regions are addressed by varying the spacer thickness. Furthermore, by varying the properties of the mirrors of the optical filters, more closely spaced wavelengths of filters may be achieved in comparison to varying the spacer thickness, since the mirrors may not be constrained by material properties and deposition precision of the spacer. Thus, construction cost and yield loss are reduced. For example, a design that spans three mirrors may be reduced from <NUM> coating runs to <NUM> coating runs while realizing <NUM> additional spectral channels in comparison to a filter generated by varying spacer thickness. Furthermore, a silicon-range (e.g., <NUM> to <NUM> nanometers (nm)) spectroscopic filter may be generated using <NUM> coating runs. These techniques can also be applied for etching methods of creating multispectral filters.

<FIG> is a diagram illustrating a side-view of an example optical filter <NUM>. As shown in <FIG>, example optical filter <NUM> includes a first pair of mirrors <NUM> comprising mirror <NUM>-<NUM> and mirror <NUM>-<NUM>, a second pair of mirrors <NUM> comprising mirror <NUM>-<NUM> and mirror <NUM>-<NUM>, and a third pair of mirrors <NUM> comprising mirror <NUM>-<NUM> and mirror <NUM>-<NUM>. Each mirror of the first pair of mirrors <NUM>, the second pair of mirrors <NUM>, or the third pair of mirrors <NUM> may comprise one or more metals, one or more dielectric materials, and/or the like. Each mirror in a pair of mirrors may have the same or similar (e.g., the same within a manufacturing tolerance) optical properties (e.g., may have a same or a similar amount of reflectivity, a same or a similar amount of transmission, a same or a similar amount of absorbency, and/or the like for a particular wavelength range). In some implementations, the first pair of mirrors <NUM> may be configured (e.g., as individual mirrors and/or as a pair of mirrors) to reflect a first portion of an electromagnetic spectrum (e.g., blue light); the second pair of mirrors <NUM> may be configured (e.g., as individual mirrors and/or as a pair of mirrors) to reflect a second portion of the electromagnetic spectrum (e.g., green light); and/or the third pair of mirrors <NUM> may be configured (e.g., as individual mirrors and/or as a pair of mirrors) to reflect a third portion of the electromagnetic spectrum (e.g., red light).

As further shown in <FIG>, a first baseline layer <NUM> may be positioned between the first pair of mirrors <NUM> (e.g., the first baseline layer <NUM> may be disposed between mirror <NUM>-<NUM> and mirror <NUM>-<NUM>) and a second baseline layer <NUM> may be positioned between the second pair of mirrors <NUM> (e.g., the second baseline layer <NUM> may be disposed between mirror <NUM>-<NUM> and <NUM>-<NUM>). For example, as shown in <FIG>, first baseline layer <NUM> may be disposed on a top surface of mirror <NUM>-<NUM> and positioned below a bottom surface of mirror <NUM>-<NUM>, and second baseline layer <NUM> may be disposed on a top surface of mirror <NUM>-<NUM> and positioned below a bottom surface of mirror <NUM>-<NUM>. The first baseline layer <NUM> may have a thickness based on the first portion of the electromagnetic spectrum (e.g., a thickness that facilitates reflection of light associated with the first portion of the electromagnetic spectrum by the first pair of mirrors <NUM>), and the second baseline layer <NUM> may have a thickness based on the second portion of the electromagnetic spectrum (e.g., a thickness that facilitates reflection of light associated with the second portion of the electromagnetic spectrum by the second pair of mirrors <NUM>).

As further shown in <FIG>, a common spacer <NUM> may be positioned between the first pair of mirrors <NUM> (e.g., the common spacer <NUM> may be disposed between mirror <NUM>-<NUM> and mirror <NUM>-<NUM>), the second pair of mirrors <NUM> (e.g., the common spacer <NUM> may be disposed between mirror <NUM>-<NUM> and mirror <NUM>-<NUM>), the third pair of mirrors <NUM> (e.g., the common spacer <NUM> may be disposed between mirror <NUM>-<NUM> and mirror <NUM>-<NUM>). For example, as shown in <FIG>, the common spacer <NUM> be disposed on a top surface of the first baseline layer <NUM> (e.g., positioned above the top surface of mirror <NUM>-<NUM> and below the bottom surface of mirror <NUM>-<NUM>), on a top surface of the second baseline layer <NUM> (e.g., positioned above the top surface of mirror <NUM>-<NUM> and below the bottom surface of mirror <NUM>-<NUM>), and/or on a top surface of mirror <NUM>-<NUM> (e.g., positioned above the top surface of mirror <NUM>-<NUM> and below the bottom surface of mirror <NUM>-<NUM>).

In some implementations, the common spacer <NUM> may comprise one or more layers (e.g., one or more spacer layers). In some implementations, the common spacer <NUM> may comprise less than a threshold number of layers, such as <NUM> layers. As further shown in <FIG>, a thickness of the common spacer <NUM> may vary across the example optical filter <NUM>. For example, the common spacer <NUM> may include a plurality of sections where one section comprises a number of layers that is different than a number of layers of another section. As further shown in <FIG>, a varying pattern of thickness of the common spacer <NUM> across the first pair of mirrors <NUM> may be the same as a varying pattern of thickness of the common spacer <NUM> across the second pair of mirrors <NUM> and/or the third pair of mirrors <NUM>.

Other examples are contemplated and may differ from what is described with regard to <FIG>.

<FIG> is a plot <NUM> of example transmission percentages associated with the example optical filter <NUM>. As shown in <FIG>, the example optical filter <NUM> may filter light associated with a portion of the electromagnetic spectrum (e.g., from about <NUM> to about <NUM>). As further shown in <FIG>, the example optical filter <NUM> provides a transmission percentage above <NUM>% for nearly all wavelengths (and above <NUM>% for most wavelengths) within the portion of the electromagnetic spectrum. Other examples are contemplated and may differ from what is described with regard to <FIG>.

<FIG> is a diagram illustrating a top-view of an example optical filter <NUM> described herein. As shown in <FIG>, the example optical filter <NUM> may be associated with three sections, section <NUM>, section <NUM>, and section <NUM>. Each section may be associated with a pair of mirrors and a common spacer (not visible in <FIG>) that may be positioned between the respective pair of mirrors of each section (e.g., as described herein in relation to <FIG>). As further shown in <FIG>, each section may include a respective number of channels. For example, section <NUM> may include <NUM> channels (e.g., <NUM>×<NUM> channels), section <NUM> may include <NUM> channels (e.g., <NUM>×<NUM> channels), and section <NUM> may include <NUM> channels (e.g., <NUM>×<NUM> channels). Accordingly, example optical filter <NUM> may include <NUM> channels. Other implementations are also contemplated, where example optical filter <NUM> may include <NUM> channels, <NUM> channels, <NUM> channels, and/or the like.

<FIG> is a diagram illustrating a side-view of an example optical filter <NUM>. As shown in <FIG>, example optical filter <NUM> includes a first pair of mirrors <NUM> comprising mirror <NUM>-<NUM> and mirror <NUM>-<NUM>, a second pair of mirrors <NUM> comprising mirror <NUM>-<NUM> and mirror <NUM>-<NUM>, a third pair of mirrors <NUM> comprising mirror <NUM>-<NUM> and mirror <NUM>-<NUM>, a fourth pair of mirrors <NUM> comprising mirror <NUM>-<NUM> and mirror <NUM>-<NUM>, and a fifth pair of mirrors <NUM> comprising mirror <NUM>-<NUM> and mirror <NUM>-<NUM>. Each mirror of the first pair of mirrors <NUM>, the second pair of mirrors <NUM>, the third pair of mirrors <NUM>, the fourth pair of mirrors <NUM>, or the fifth pair of mirrors <NUM> may comprise one or more metals, one or more dielectric materials, and/or the like. Each mirror in a pair of mirrors may have the same or similar optical properties (e.g., may have a same or a similar amount of reflectivity, a same or a similar amount of transmission, a same or a similar amount of absorbency, and/or the like for a particular wavelength range). In some implementations, the first pair of mirrors <NUM> may be configured (e.g., as individual mirrors and/or as a pair of mirrors) to reflect a first portion of an electromagnetic spectrum (e.g., blue light); the second pair of mirrors <NUM> may be configured (e.g., as individual mirrors and/or as a pair of mirrors) to reflect a second portion of the electromagnetic spectrum (e.g., green light); the third pair of mirrors <NUM> may be configured (e.g., as individual mirrors and/or as a pair of mirrors) to reflect a third portion of the electromagnetic spectrum (e.g., red light); the fourth pair of mirrors <NUM> may be configured (e.g., as individual mirrors and/or as a pair of mirrors) to reflect a fourth portion of the electromagnetic spectrum (e.g., a first portion of near-infrared light); and/or the fifth pair of mirrors <NUM> may be configured (e.g., as individual mirrors and/or as a pair of mirrors) to reflect a fifth portion of the electromagnetic spectrum (e.g., a second portion of near-infrared light).

As further shown in <FIG>, a first baseline layer <NUM> may be positioned between the first pair of mirrors <NUM> (e.g., the first baseline layer <NUM> may be disposed between mirror <NUM>-<NUM> and mirror <NUM>-<NUM>), a second baseline layer <NUM> may be positioned between the second pair of mirrors <NUM> (e.g., the second baseline layer <NUM> may be disposed between mirror <NUM>-<NUM> and <NUM>-<NUM>), a third baseline layer <NUM> may be positioned between the fourth pair of mirrors <NUM> (e.g., the third baseline layer <NUM> may be disposed between mirror <NUM>-<NUM> and <NUM>-<NUM>), and a fourth baseline layer <NUM> may be positioned between the fifth pair of mirrors <NUM> (e.g., the fourth baseline layer <NUM> may be disposed between mirror <NUM>-<NUM> and <NUM>-<NUM>). For example, as shown in <FIG>, first baseline layer <NUM> may be disposed on a top surface of mirror <NUM>-<NUM> and positioned below a bottom surface of mirror <NUM>-<NUM>, second baseline layer <NUM> may be disposed on a top surface of mirror <NUM>-<NUM> and positioned below a bottom surface of mirror <NUM>-<NUM>, third baseline layer <NUM> may be disposed on a top surface of mirror <NUM>-<NUM> and positioned below a bottom surface of mirror <NUM>-<NUM>, and/or fourth baseline layer <NUM> may be disposed on a top surface of mirror <NUM>-<NUM> and positioned below a bottom surface of mirror <NUM>-<NUM>. The first baseline layer <NUM> may have a thickness based on the first portion of the electromagnetic spectrum (e.g., a thickness that facilitates reflection of light associated with the first portion of the electromagnetic spectrum by the first pair of mirrors <NUM>), the second baseline layer <NUM> may have a thickness based on the second portion of the electromagnetic spectrum (e.g., a thickness that facilitates reflection of light associated with the second portion of the electromagnetic spectrum by the second pair of mirrors <NUM>), the third baseline layer <NUM> may have a thickness based on the fourth portion of the electromagnetic spectrum (e.g., a thickness that facilitates reflection of light associated with the fourth portion of the electromagnetic spectrum by the fourth pair of mirrors <NUM>), and/or the fourth baseline layer <NUM> may have a thickness based on the fifth portion of the electromagnetic spectrum (e.g., a thickness that facilitates reflection of light associated with the fifth portion of the electromagnetic spectrum by the fifth pair of mirrors <NUM>).

As further shown in <FIG>, a common spacer <NUM> may be positioned between the first pair of mirrors <NUM> (e.g., the common spacer <NUM> may be disposed between mirror <NUM>-<NUM> and mirror <NUM>-<NUM>), the second pair of mirrors <NUM> (e.g., the common spacer <NUM> may be disposed between mirror <NUM>-<NUM> and mirror <NUM>-<NUM>), the third pair of mirrors <NUM> (e.g., the common spacer <NUM> may be disposed between mirror <NUM>-<NUM> and mirror <NUM>-<NUM>), the fourth pair of mirrors <NUM> (e.g., the common spacer <NUM> may be disposed between mirror <NUM>-<NUM> and mirror <NUM>-<NUM>), and/or the fifth pair of mirrors <NUM> (e.g., the common spacer <NUM> may be disposed between mirror <NUM>-<NUM> and mirror <NUM>-<NUM>). For example, as shown in <FIG>, the common spacer <NUM> may be disposed on a top surface of the first baseline layer <NUM> (e.g., positioned above the top surface of mirror <NUM>-<NUM> and below the bottom surface of mirror <NUM>-<NUM>), on a top surface of the second baseline layer <NUM> (e.g., positioned above the top surface of mirror <NUM>-<NUM> and below the bottom surface of mirror <NUM>-<NUM>), on a top surface of mirror <NUM>-<NUM> (e.g., positioned above the top surface of mirror <NUM>-<NUM> and below the bottom surface of mirror <NUM>-<NUM>), on a top surface of the third baseline layer <NUM> (e.g., positioned above the top surface of mirror <NUM>-<NUM> and below the bottom surface of mirror <NUM>-<NUM>), and/or on a top surface of the fourth baseline layer <NUM> (e.g., positioned above the top surface of mirror <NUM>-<NUM> and below the bottom surface of mirror <NUM>-<NUM>).

In some implementations, the common spacer <NUM> may comprise one or more layers (e.g., one or more spacer layers). In some implementations, the common spacer <NUM> may comprise less than a threshold number of layers, such as <NUM> layers. As further shown in <FIG>, a thickness of the common spacer <NUM> may vary across the example optical filter <NUM>. For example, the common spacer <NUM> may include a plurality of sections where one section comprises a number of layers that is different than a number of layers of another section. As further shown in <FIG>, a varying pattern of thickness of the common spacer <NUM> across the first pair of mirrors <NUM> may be the same as a varying pattern of thickness of the common spacer <NUM> across the second pair of mirrors <NUM>, the third pair of mirrors <NUM>, the fourth pair of mirrors <NUM>, and/or the fifth pair of mirrors <NUM>.

<FIG> is a plot <NUM> of example transmission percentages associated with the example optical filter <NUM>. As shown in <FIG>, the optical filter <NUM> may filter light associated with a portion of the electromagnetic spectrum (e.g., from about <NUM> to about <NUM>). As further shown in <FIG>, the example optical filter <NUM> provides a transmission percentage above <NUM>% for nearly all wavelengths (and above <NUM>% for most wavelengths) within the portion of the electromagnetic spectrum. Other examples are contemplated and may differ from what is described with regard to <FIG>.

<FIG> is a diagram illustrating a side-view of an example optical filter <NUM>. As shown in <FIG>, example optical filter <NUM> includes a mirror <NUM>, a mirror <NUM>, a common spacer <NUM>, a mirror <NUM>, and a mirror <NUM>. As shown in <FIG>, the common spacer <NUM> may be positioned between a first layer of mirrors (e.g., comprising mirror <NUM> and mirror <NUM>) and a second layer of mirrors (e.g., comprising mirror <NUM> and mirror <NUM>) in a similar manner as that described herein in relation to common spacer <NUM> and common spacer <NUM>. Common spacer <NUM> may comprise one or more layers and may vary in thickness across the example optical filter <NUM> in a similar manner as that described herein in relation to common spacer <NUM> and common spacer <NUM>.

As shown in <FIG>, mirror <NUM> may be paired with mirror <NUM> (e.g., mirror <NUM> is above a top surface of mirror <NUM> and mirror <NUM> is below a bottom surface of mirror <NUM>) and mirror <NUM> may be paired with mirror <NUM> (e.g., mirror <NUM> is above a top surface of mirror <NUM> and mirror <NUM> is below a bottom surface of mirror <NUM>). Each mirror may comprise one or more metals, one or more dielectric materials, and/or the like.

As indicated by the diagonal shading pattern of mirror <NUM> and mirror <NUM> in <FIG>, mirror <NUM> and mirror <NUM> may have the same or similar optical properties (e.g., may have a same or a similar amount of reflectivity, a same or a similar amount of transmission, a same or a similar amount of absorbency, and/or the like for a particular wavelength range). In some implementations, mirror <NUM> and mirror <NUM> may be configured to reflect a first portion of an electromagnetic spectrum (e.g., blue light) where mirror <NUM> is configured to reflect a first wavelength range of the first portion of the electromagnetic spectrum and mirror <NUM> is configured to reflect a second wavelength range of the first portion of the electromagnetic spectrum (e.g., mirror <NUM> and mirror <NUM> may be "mismatched" in the same color space), where a difference between a representative wavelength of the first wavelength range (e.g., the median wavelength of the first wavelength range) and a representative wavelength of the second wavelength range (e.g., the median wavelength of the second wavelength range) is less than or equal to a threshold, such as <NUM>.

As indicated by the dotted shading pattern of mirror <NUM> and mirror <NUM> in <FIG>, mirror <NUM> and mirror <NUM> may have the same or similar optical properties (e.g., may have a same or a similar amount of reflectivity, a same or a similar amount of transmission, a same or a similar amount of absorbency, and/or the like for a particular wavelength range). In some implementations, mirror <NUM> and mirror <NUM> may be configured to reflect a second portion of the electromagnetic spectrum (e.g., green light) where mirror <NUM> is configured to reflect a first wavelength range of the second portion of the electromagnetic spectrum and mirror <NUM> is configured to reflect a second wavelength range of the second portion of the electromagnetic spectrum (e.g., mirror <NUM> and mirror <NUM> may be "mismatched" in the same color space), where a difference between a representative wavelength of the first wavelength range (e.g., the median wavelength of the first wavelength range) and a representative wavelength of the second wavelength range (e.g., the median wavelength of the second wavelength range) is less than or equal to a threshold, such as <NUM>.

In this way, example optical filter <NUM> may provide a first pair of mismatched mirrors (e.g., mirror <NUM> and mirror <NUM>) to provide greater fidelity in discerning wavelength ranges associated with the first portion of the electromagnetic spectrum and a second pair of mismatched mirrors (e.g., mirror <NUM> and mirror <NUM>) to provide greater fidelity in discerning wavelength ranges associated with the second portion of the electromagnetic spectrum.

<FIG> is a plot <NUM> of example transmission percentages associated with the example optical filter <NUM>. As shown in <FIG>, the example optical filter <NUM> may filter light associated with a portion of the electromagnetic spectrum (e.g., from about <NUM> to about <NUM>). As further shown in <FIG>, the example optical filter <NUM> provides a transmission percentage above <NUM>% for nearly all wavelengths (and above <NUM>% for most wavelengths) within the portion of the electromagnetic spectrum. As further shown in <FIG>, a first mirror of a pair of mirrors of the example optical filter <NUM> may transmit, for a particular wavelength range, a first wavelength of light <NUM> at a first transmission percentage and may transmit a second wavelength of light <NUM> (e.g., that has a wavelength shift that is less than or equal to a threshold, such as <NUM>, from the first wavelength) at a second transmission percentage. As shown in <FIG>, for any wavelength range, the first transmission percentage is higher than the second transmission percentage.

<FIG> is a diagram illustrating an example optical filter <NUM>. As shown in <FIG>, example optical filter <NUM> includes a first mirror <NUM>, a second mirror <NUM>, a common spacer <NUM>, and third mirror <NUM>. As shown in <FIG>, the common spacer <NUM> may be positioned between a layer of mirrors (e.g., comprising mirror <NUM> and mirror <NUM>) and mirror <NUM> in a similar manner as that described herein in relation to common spacer <NUM> and common spacer <NUM>. Common spacer <NUM> may comprise one or more layers and may vary in thickness across the example optical filter <NUM> in a similar manner as that described herein in relation to common spacer <NUM> and common spacer <NUM>.

As shown in <FIG>, mirror <NUM> may be paired with mirror <NUM> (e.g., mirror <NUM> is above a top surface of mirror <NUM> and mirror <NUM> is below a bottom surface of mirror <NUM>) and mirror <NUM> may be paired with mirror <NUM> (e.g., mirror <NUM> is above a top surface of mirror <NUM> and mirror <NUM> is below a bottom surface of mirror <NUM>). Each mirror may comprise one or more metals, one or more dielectric materials, and/or the like. As indicated by the different shading patterns of the mirrors, mirror <NUM>, mirror <NUM>, and mirror <NUM> may have different optical properties (e.g., each mirror may have a different amount of reflectivity, a different amount of transmission, a different amount of absorbency, and/or the like for a particular wavelength range). In some implementations, the pair of mirror <NUM> and mirror <NUM> may be configured to reflect a portion of an electromagnetic spectrum (e.g., blue light) where mirror <NUM> is configured to reflect a first wavelength range of the portion of the electromagnetic spectrum and mirror <NUM> is configured to reflect a second wavelength range of the portion of the electromagnetic spectrum (e.g., mirror <NUM> and mirror <NUM> may be "mismatched" in the same color space). In some implementations, the pair of mirror <NUM> and mirror <NUM> may be configured to reflect the portion of the electromagnetic spectrum where mirror <NUM> is configured to reflect a third wavelength range of the portion of the electromagnetic spectrum and mirror <NUM> is configured to reflect the second wavelength range of the portion of the electromagnetic spectrum (e.g., mirror <NUM> and mirror <NUM> may be "mismatched" in the same color space).

In this way, example optical filter <NUM> may provide a first pair of mismatched mirrors (e.g., mirror <NUM> and mirror <NUM>) and second pair of mismatched mirrors (e.g., mirror <NUM> and mirror <NUM>) to provide greater fidelity in discerning wavelength ranges associated with the portion of the electromagnetic spectrum.

<FIG> is a diagram illustrating an example optical filter <NUM>. As shown in <FIG>, example optical filter <NUM> includes a first mirror <NUM>, a second mirror <NUM>, a common spacer <NUM>, a third mirror <NUM>, and a fourth mirror <NUM>. As shown in <FIG>, the common spacer <NUM> may be positioned between a first layer of mirrors (e.g., comprising mirror <NUM> and mirror <NUM>) and a second layer of mirrors (e.g., comprising mirror <NUM> and mirror <NUM>) in a similar manner as that described herein in relation to common spacer <NUM> and common spacer <NUM>. Common spacer <NUM> may comprise one or more layers and may vary in thickness across the example optical filter <NUM> in a similar manner as that described herein in relation to common spacer <NUM> and common spacer <NUM>.

As shown in <FIG>, mirror <NUM> may be paired with mirror <NUM> (e.g., mirror <NUM> is above a top surface of mirror <NUM> and mirror <NUM> is below a bottom surface of mirror <NUM>) and mirror <NUM> may be paired with mirror <NUM> (e.g., mirror <NUM> is above a top surface of mirror <NUM> and mirror <NUM> is below a bottom surface of mirror <NUM>). Each mirror may comprise one or more metals, one or more dielectric materials, and/or the like. As indicated by the different shading patterns of the mirrors, mirror <NUM>, mirror <NUM>, mirror <NUM>, and mirror <NUM> may have different optical properties (e.g., each mirror may have a different amount of reflectivity, a different amount of transmission, a different amount of absorbency, and/or the like for a particular wavelength range).

In some implementations, mirror <NUM> and mirror <NUM> may be configured to reflect a first portion of an electromagnetic spectrum (e.g., blue light) where mirror <NUM> is configured to reflect a first wavelength range of the first portion of the electromagnetic spectrum and mirror <NUM> is configured to reflect a second wavelength range of the first portion of the electromagnetic spectrum (e.g., mirror <NUM> and mirror <NUM> may be "mismatched" in the same color space), where a difference between a representative wavelength of the first wavelength range (e.g., the median wavelength of the first wavelength range) and a representative wavelength of the second wavelength range (e.g., the median wavelength of the second wavelength range) is greater than a threshold, such as <NUM>. In some implementations, mirror <NUM> and mirror <NUM> may be configured to reflect a second portion of the electromagnetic spectrum (e.g., green light) where mirror <NUM> is configured to reflect a first wavelength range of the second portion of the electromagnetic spectrum and mirror <NUM> is configured to reflect a second wavelength range of the second portion of the electromagnetic spectrum (e.g., mirror <NUM> and mirror <NUM> may be "mismatched" in the same color space), where a difference between a representative wavelength of the first wavelength range (e.g., the median wavelength of the first wavelength range) and a representative wavelength of the second wavelength range (e.g., the median wavelength of the second wavelength range) is greater than a threshold, such as <NUM>.

<FIG> is a flowchart of an example process <NUM> associated with manufacturing an optical filter (e.g., an optical filter with at least a threshold number of channels, such as <NUM> channels, <NUM> channels, <NUM> channels, and/or the like). In some implementations, one or more process blocks of <FIG> may be performed by a manufacturing device. In some implementations, one or more process blocks of <FIG> may be performed by another device or a group of devices separate from or including the manufacturing device.

As shown in <FIG>, process <NUM> may include depositing, on a substrate, a first mirror, a second mirror, and a third mirror (block <NUM>). In some implementations, the first mirror, the second mirror, and the third mirror do not overlap each other.

As further shown in <FIG>, process <NUM> may include depositing, above the first mirror, the second mirror, and the third mirror, a common spacer (block <NUM>). In some implementations, depositing the common spacer may comprise depositing less than ten spacer layers.

In some implementations, process <NUM> may include depositing, on the first mirror, a first baseline spacer; depositing, on the second mirror, a second baseline spacer; depositing, on the third mirror, a third baseline spacer; and depositing the common spacer on the first baseline spacer, the second baseline spacer, and the third baseline spacer.

As further shown in <FIG>, process <NUM> may include depositing, on the common spacer and opposite the first mirror, a fourth mirror (block <NUM>). In some implementations, the fourth mirror is paired with the first mirror to reflect a first portion of an electromagnetic spectrum.

As further shown in <FIG>, process <NUM> may include depositing, on the common spacer and opposite the second mirror, a fifth mirror (block <NUM>). In some implementations, the fifth mirror is paired with the second mirror to reflect a second portion of the electromagnetic spectrum.

As further shown in <FIG>, process <NUM> may include depositing, on the common spacer and opposite the third mirror, a sixth mirror (block <NUM>). In some implementations, the sixth mirror is paired with the third mirror to reflect a third portion of the electromagnetic spectrum.

In some implementations, depositing the common spacer comprises depositing a plurality of spacer layers such that the common spacer has a thickness that varies in a same pattern between the first mirror and the fourth mirror, between the second mirror and the fifth mirror, and between the third mirror and the sixth mirror.

In some implementations, depositing the first baseline spacer comprises depositing the first baseline spacer at a first thickness based on the first portion of the electromagnetic spectrum; depositing the second baseline spacer comprises depositing the second baseline spacer at a second thickness based on the second portion of the electromagnetic spectrum; and depositing the third baseline spacer comprises depositing the third baseline spacer at a third thickness based on the third portion of the electromagnetic spectrum.

In some implementations, the first portion of the electromagnetic spectrum is in a visible range of the electromagnetic spectrum; the second portion of the electromagnetic spectrum is in the visible range of the electromagnetic spectrum, and the third portion of the electromagnetic spectrum is in the visible range of the electromagnetic spectrum. In some implementations, the first portion of the electromagnetic spectrum is in a visible range of the electromagnetic spectrum; the second portion of the electromagnetic spectrum is in a first portion of the near-infrared range of the electromagnetic spectrum, and the third portion of the electromagnetic spectrum is in a second portion of the near-infrared range of the electromagnetic spectrum.

As shown in <FIG>, process <NUM> may include depositing, on a substrate, a first mirror and a second mirror, wherein the first mirror and the second mirror do not overlap (block <NUM>). In some implementations, the first mirror and the second mirror do not overlap. In some implementations, the first mirror is to reflect a set of first wavelengths of an electromagnetic spectrum; the second mirror is to reflect a set of second wavelengths of the electromagnetic spectrum; and second wavelengths of the set of second wavelengths are shifted with respect to first wavelengths of the set of first wavelengths. In some implementations, at least one of the set of first wavelengths or the set of second wavelengths is in a visible range of the electromagnetic spectrum and/or the near-infrared range of the electromagnetic spectrum.

As further shown in <FIG>, process <NUM> may include depositing, above the first mirror and the second mirror, a common spacer (block <NUM>).

As further shown in <FIG>, process <NUM> may include depositing, on the common spacer, opposite the first mirror, and opposite the second mirror, one or more additional mirrors (block <NUM>). The one or more additional mirrors may reflect one or more sets of other wavelengths that are different from the set of first wavelengths and different from the set of second wavelengths.

In some implementations, depositing the one or more additional mirrors comprises: depositing, opposite the first mirror, a third mirror paired with the first mirror to reflect the set of first wavelengths, and depositing, opposite the second mirror, a fourth mirror paired with the second mirror to reflect the set of second wavelengths. In some implementations, depositing the one or more additional mirrors comprises: depositing, opposite the first mirror and opposite the second mirror, a third mirror paired with the first mirror to reflect the set of first wavelengths.

Process <NUM> may include additional implementations, such as any single implementation or any combination of implementations described in connection with one or more other processes described elsewhere herein.

As used herein, satisfying a threshold may, depending on the context, refer to a value being greater than the threshold, more than the threshold, higher than the threshold, greater than or equal to the threshold, less than the threshold, fewer than the threshold, lower than the threshold, less than or equal to the threshold, equal to the threshold, and/or the like, depending on the context.

Claim 1:
An optical filter, comprising:
a first pair of mirrors (<NUM>);
a second pair of mirrors (<NUM>);
wherein the second pair of mirrors and the first pair of mirrors reflect different portions of an electromagnetic spectrum; and
a common spacer (<NUM>) positioned between the first pair of mirrors and between the second pair of mirrors.
wherein a thickness of the common spacer across the first pair of mirrors varies in a same pattern as a thickness of the common spacer across the second pair of mirrors.