PATENT DOCUMENT

Publication Number: US-10705347-B2
Application Number: US-201916399937-A
Country: US
Kind Code: B2

Title: Wafer-level high aspect ratio beam shaping

Abstract:
A light-emitting device includes a semiconductor substrate, a surface-emitting semiconductor light source on the semiconductor substrate, a monolithic first dielectric, and a second dielectric. The monolithic first dielectric is transparent to light emitted by the light source and includes first and second micro-lenses adjacent an aperture of the light source and having axes parallel to and offset from an axis of a beam of light emitted by the light source, and a saddle-shaped lens over the aperture of the light source. The saddle-shaped lens connects the first and second micro-lenses and reshapes the beam of light emitted by the light source to have a high aspect ratio. The second dielectric is transparent to light emitted by the light source and encapsulates a light emission surface of the saddle-shaped lens. The second dielectric has a higher refractive index than the monolithic first dielectric.

Claims:
What is claimed is: 
     
       1. A light-emitting device, comprising:
 a semiconductor substrate; 
 a surface-emitting semiconductor light source on the semiconductor substrate; 
 a monolithic first dielectric, transparent to light emitted by the light source, comprising:
 first and second micro-lenses adjacent an aperture of the light source and having axes parallel to and offset from an axis of a beam of light emitted by the light source; and 
 a saddle-shaped lens over the aperture of the light source, the saddle-shaped lens connecting the first and second micro-lenses and reshaping the beam of light emitted by the light source to have a high aspect ratio; and 
 
 a second dielectric, transparent to light emitted by the light source, encapsulating a light emission surface of the saddle-shaped lens; wherein: 
 the second dielectric has a higher refractive index than the monolithic first dielectric. 
 
     
     
       2. The light-emitting device of  claim 1 , wherein:
 the light source comprises a vertical-cavity surface-emitting laser (VCSEL); 
 the saddle-shaped lens reshapes the beam of light emitted by the VCSEL to have a beam divergence of greater than or equal to 120 degrees in a first plane including the axis of the beam of light, and less than or equal to 20 degrees in a second plane including the axis of the beam of light; 
 the first plane is perpendicular to the second plane; and 
 the second dielectric has a light emission surface parallel to a surface of the semiconductor substrate containing the aperture. 
 
     
     
       3. The light-emitting device of  claim 1 , wherein the second dielectric has a light emission surface parallel to a surface of the semiconductor substrate containing the aperture. 
     
     
       4. The light-emitting device of  claim 1 , wherein:
 the saddle-shaped lens reshapes the beam of light emitted by the light source to have a beam divergence of greater than or equal to 120 degrees in a first direction, and less than or equal to 20 degrees in a second direction; and 
 the first direction is perpendicular to the second direction. 
 
     
     
       5. The light-emitting device of  claim 1 , wherein:
 the light emission surface of the saddle-shaped lens contacts the semiconductor substrate or a layer thereon at a slope angle equal to or larger than forty (40) degrees. 
 
     
     
       6. The light-emitting device of  claim 1 , wherein a second refractive index of the second dielectric is more than 0.2 times larger than a first refractive index of the monolithic first dielectric. 
     
     
       7. The light-emitting device of  claim 1 , wherein the light source comprises at least one of a vertical-cavity surface-emitting laser (VCSEL) or a vertical external-cavity surface-emitting laser (VECSEL). 
     
     
       8. The light-emitting device of  claim 1 , wherein the light source comprises an organic light-emitting diode (OLED). 
     
     
       9. A light-emitting device, comprising:
 a semiconductor substrate; 
 a surface-emitting semiconductor light source on the semiconductor substrate; 
 a first dielectric, transparent to light emitted by the light source, comprising a saddle-shaped lens over an aperture of the light source, the saddle-shaped lens reshaping a beam of light emitted by the light source to have a high aspect ratio; and 
 a second dielectric, transparent to light emitted by the light source, encapsulating a light emission surface of the saddle-shaped lens; wherein: 
 the second dielectric has a higher refractive index than the first dielectric. 
 
     
     
       10. The light-emitting device of  claim 9 , wherein:
 the first dielectric further comprises:
 a first dielectric feature adjacent the aperture of the light source; and 
 a second dielectric feature adjacent the aperture of the light source; wherein: 
 
 the first dielectric is monolithic, with the first dielectric feature connected to the second dielectric feature by the saddle-shaped lens. 
 
     
     
       11. The light-emitting device of  claim 9 , wherein:
 the saddle-shaped lens has a height and a width at a center of a length of the saddle-shaped lens; and 
 the length is greater than the width. 
 
     
     
       12. The light-emitting device of  claim 9 , wherein the second dielectric has a light emission surface parallel to a surface of the semiconductor substrate containing the aperture. 
     
     
       13. The light-emitting device of  claim 9 , wherein the light source comprises a laser. 
     
     
       14. The light-emitting device of  claim 9 , wherein the light source comprises a light-emitting diode (LED). 
     
     
       15. A light-emitting device, comprising:
 a set of one or more semiconductor die; 
 a set of surface-emitting semiconductor light sources on the set of one or more semiconductor die, the set of surface-emitting semiconductor light sources including a first light source and a second light source; 
 a first saddle-shaped lens connecting a first pair of micro-lenses, the first saddle-shaped lens disposed over a first aperture of the first light source; and 
 a second saddle-shaped lens connecting a second pair of micro-lenses, the second saddle-shaped lens disposed over a second aperture of the second light source; and 
 a dielectric, transparent to light emitted by the first light source and the second light source, encapsulating light emission surfaces of the first saddle-shaped lens and the second saddle-shaped lens; wherein: 
 each of the first saddle-shaped lens and the second saddle-shaped lens reshapes a beam of light emitted by the first light source or the second light source to have a high aspect ratio; 
 the first saddle-shaped lens has a different angular orientation than the second saddle-shaped lens; and 
 the dielectric has a higher refractive index than the first saddle-shaped lens and the second saddle-shaped lens. 
 
     
     
       16. The light-emitting device of  claim 15 , wherein:
 the set of surface-emitting semiconductor light sources includes a third light source; 
 the light-emitting device further comprises a third saddle-shaped lens over a third aperture of the third light source; 
 the dielectric further encapsulates a light emission surface of the third saddle-shaped lens; 
 the third saddle-shaped lens reshapes a beam of light emitted by the third light source to have a high aspect ratio; and 
 the third saddle-shaped lens has a different angular orientation than the first saddle-shaped lens and the second saddle-shaped lens. 
 
     
     
       17. The light-emitting device of  claim 16 , wherein:
 each of the first saddle-shaped lens, the second saddle-shaped lens, and the third saddle-shaped lens reshapes a beam of light to have a greatest divergence along a respective first axis, second axis, and third axis; and 
 each of the first axis, the second axis, and the third axis intersects each other of the first axis, the second axis, and the third axis. 
 
     
     
       18. The light-emitting device of  claim 17 , further comprising:
 a controller operable to activate and deactivate the first light source, the second light source, and the third light source in an alternating manner, to simulate a single, rotating, high aspect ratio, beam of light at a far field. 
 
     
     
       19. The light-emitting device of  claim 15 , further comprising:
 a controller operable to activate the first light source and the second light source at different times. 
 
     
     
       20. The light-emitting device of  claim 15 , further comprising:
 a controller operable to activate and deactivate the first light source and the second light source simultaneously.

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This application is a nonprovisional of and claims the benefit under 35 U.S.C. 119(e) of U.S. Provisional Patent Application No. 62/678,201, filed May 30, 2018, and entitled “Wafer-Level High Aspect Ratio Beam Shaping,” the contents of which are incorporated herein by reference as if fully disclosed herein. 
    
    
     FIELD 
     The described embodiments relate generally to wafer-level high aspect ratio beam shaping. More particularly, the described embodiments relate to a light-emitting device having a saddle-shaped lens that reshapes a beam of light to have a high aspect ratio. 
     BACKGROUND 
     Many electronic devices incorporate a light-emitting device. For example, a digital camera, smart phone, or tablet computer may have a camera associated with a camera flash. In some cases, such devices may be able to operate the camera flash in a steady-state ON mode, as may be required to provide a flashlight function or illumination for video recording. An electronic device may also or alternatively include a biosensor or bioauthentication sensor (e.g., a fingerprint sensor or camera), and a light source operable to provide visible or invisible illumination for the purpose of illuminating a body part that is to be scanned or imaged by the biosensor or bioauthentication sensor. Some electronic devices or systems, such as a set of one or more components forming part of a navigation system of a motor vehicle, may include a light source operable to provide illumination for a scanning depth sensor, single photon avalanche detector (SPAD) array, or other sensor used for vehicle navigation. An electronic device may also or alternatively include an optical communication system that emits visible or invisible light. 
     In some cases, it may be desirable to emit light having a high aspect ratio from an electronic device. For example, it may be desirable to emit light having a high aspect ratio when capturing a panoramic photo or video. It may also be desirable to emit light having a high aspect ratio when scanning or imaging a body part for purposes of analyzing the body part or authenticating a user of a device. High aspect ratio light may also be useful when operating a camera or sensor in a line-scan mode. 
     SUMMARY 
     Embodiments of the systems, devices, methods, and apparatus described in the present disclosure are directed to wafer-level high aspect ratio beam shaping. In accordance with described wafer processing techniques, a saddle-shaped lens may be formed over a surface-emitting semiconductor light source (e.g., a vertical-cavity surface-emitting laser (VCSEL), a vertical external-cavity surface-emitting laser (VECSEL), or a light-emitting diode (LED) (e.g., an organic LED (OLED), a resonant-cavity LED (RC-LED), a micro LED (mLED), a superluminescent LED (SLED), and so on). In some embodiments, a saddle-shaped lens may be formed over each light source in a set of light sources formed on a wafer, and the light sources and their associated lenses (or sets thereof) may be diced from the wafer after forming the saddle-shaped lenses. Each saddle-shaped lens may reshape a beam of light, emitted by a respective light source, to have a high aspect ratio. In some cases, different saddle-shaped lenses having different angular orientations may be formed on a wafer, or different saddle-shaped lenses having different aspect ratios may be formed on a wafer. 
     In a first aspect, the present disclosure describes a light-emitting device. The light-emitting device may include a semiconductor substrate, a surface-emitting semiconductor light source on the semiconductor substrate, a monolithic first dielectric, and a second dielectric. The monolithic first dielectric may be transparent to light emitted by the light source and include first and second micro-lenses and a saddle-shaped lens. The first and second micro-lenses may be adjacent an aperture of the light source and have axes parallel to and offset from an axis of a beam of light emitted by the light source. The saddle-shaped lens may be disposed over the aperture of the light source. The saddle-shaped lens may connect the first and second micro-lenses and reshape the beam of light emitted by the light source to have a high aspect ratio. The second dielectric may be transparent to light emitted by the light source, and may encapsulate a light emission surface of the saddle-shaped lens. The second dielectric may have a higher refractive index than the monolithic first dielectric. 
     In another aspect, the present disclosure describes another light-emitting device. The light-emitting device may include a semiconductor substrate, a surface-emitting semiconductor light source on the semiconductor substrate, a first dielectric, and a second dielectric. The first dielectric may be transparent to light emitted by the light source, and may include a saddle-shaped lens over an aperture of the light source. The saddle-shaped lens may reshape a beam of light emitted by the light source to have a high aspect ratio. The second dielectric may be transparent to light emitted by the light source, and may encapsulate a light emission surface of the saddle-shaped lens. The second dielectric may have a higher refractive index than the first dielectric. 
     In still another aspect of the disclosure, another light-emitting device is described. The light-emitting device may include a set of one or more semiconductor die, a set of surface-emitting semiconductor light sources, a first saddle-shaped lens, a second saddle-shaped lens, and a dielectric. The set of surface-emitting semiconductor light sources may be disposed on the set of one or more semiconductor die, and may include a first light source and a second light source. The first saddle-shaped lens may connect a first pair of micro-lenses, and may be disposed over a first aperture of the first light source. The second saddle-shaped lens may connect a second pair of micro-lenses, and may be disposed over a second aperture of the second light source. The dielectric may be transparent to light emitted by the first light source and the second light source, and may encapsulate light emission surfaces of the first saddle-shaped lens and the second saddle-shaped lens. Each of the first saddle-shaped lens and the second saddle-shaped lens may reshape a beam of light emitted by the first light source or the second light source to have a high aspect ratio. The first saddle-shaped lens may have a different angular orientation than the second saddle-shaped lens. The dielectric may have a higher refractive index than the first saddle-shaped lens and the second saddle-shaped lens. 
     In addition to the exemplary aspects and embodiments described above, further aspects and embodiments will become apparent by reference to the drawings and by study of the following description. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The disclosure will be readily understood by the following detailed description in conjunction with the accompanying drawings, wherein like reference numerals designate like structural elements, and in which: 
         FIG. 1A  shows an example of a smart phone having a camera; 
         FIG. 1B  shows an example of an electronic device having a bioauthentication sensor; 
         FIG. 1C  shows an example of a device having a navigation system; 
         FIG. 1D  shows an example of an electronic device having a light source for transmitting optical communications to a host device; 
         FIG. 2  shows a first example of a light-emitting device including a surface-emitting semiconductor light source; 
         FIG. 3A  shows a second example of a light-emitting device including a surface-emitting semiconductor light source; 
         FIG. 3B  shows a cross-section of the light-emitting device shown in  FIG. 3A ; 
         FIG. 3C  shows a divergence of light emitted across the width of the light-emitting device shown in  FIGS. 3A and 3B ; 
         FIG. 3D  shows a divergence of light emitted across the length of the light-emitting device shown in  FIGS. 3A and 3B ; 
         FIG. 4A  illustrates far field illumination provided by the light-emitting device described with reference to  FIG. 3A , in an angular space; 
         FIG. 4B  illustrates far field illumination provided by the light-emitting device described with reference to  FIG. 3A , in a position space; 
         FIG. 5  shows a first example of a method for making a plurality of light-emitting devices, including, for example, the light-emitting device described with reference to  FIG. 2 or 3A ; 
         FIGS. 6A-6H  show example cross-sections of various interim forms of light-emitting devices, which interim forms of light-emitting devices may exist after performing the operation(s) included in various blocks of the method described with reference to  FIG. 5 ; 
         FIG. 7  shows a second example of a method for making a plurality of light-emitting devices, including, for example, the light-emitting device described with reference to  FIG. 2 or 3A ; 
         FIGS. 8A-8E  show example cross-sections of a device used to make the light-emitting devices described with reference to  FIG. 7 , and  FIGS. 8F-8I  show example cross-sections of various interim forms of light-emitting devices, which interim forms of light-emitting devices may exist after performing the operation(s) included in various blocks of the method described with reference to  FIG. 5 ; 
         FIG. 9  shows a light-emitting device having two light sources; 
         FIG. 10  shows a light-emitting device having three light sources; 
         FIGS. 11A-11D  depict an illumination provided by the light-emitting device described with reference to  FIG. 10 , in a far-field plane, when light sources are positioned in close proximity to one another and turned on and off at different times, in an alternating manner; 
         FIGS. 12A and 12B  depict an illumination provided by the light-emitting device described with reference to  FIG. 10 , in different far-field planes, when light sources are positioned in close proximity to one another and turned on simultaneously; and 
         FIG. 13  shows a sample electrical block diagram of an electronic device, which electronic device may in some cases take the form of one of the devices described with reference to  FIGS. 1A-1D . 
     
    
    
     The use of cross-hatching or shading in the accompanying figures is generally provided to clarify the boundaries between adjacent elements and also to facilitate legibility of the figures. Accordingly, neither the presence nor the absence of cross-hatching or shading conveys or indicates any preference or requirement for particular materials, material properties, element proportions, element dimensions, commonalities of similarly illustrated elements, or any other characteristic, attribute, or property for any element illustrated in the accompanying figures. 
     Additionally, it should be understood that the proportions and dimensions (either relative or absolute) of the various features and elements (and collections and groupings thereof) and the boundaries, separations, and positional relationships presented therebetween, are provided in the accompanying figures merely to facilitate an understanding of the various embodiments described herein and, accordingly, may not necessarily be presented or illustrated to scale, and are not intended to indicate any preference or requirement for an illustrated embodiment to the exclusion of embodiments described with reference thereto. 
     DETAILED DESCRIPTION 
     Reference will now be made in detail to representative embodiments illustrated in the accompanying drawings. It should be understood that the following description is not intended to limit the embodiments to one preferred embodiment. To the contrary, it is intended to cover alternatives, modifications, and equivalents as can be included within the spirit and scope of the described embodiments as defined by the appended claims. 
     The following disclosure relates to wafer-level techniques for shaping a beam of light to have a high aspect ratio (e.g., shaping a beam of light to have an ultra-wide field-of-view (FoV) in one direction and a narrower FoV in an orthogonal direction). In some embodiments, the disclosed techniques may be used to produce a saddle-shaped lens over an aperture of a surface-emitting semiconductor light source. The saddle-shaped lens may be positioned between a pair of micro-lenses or other dielectric features that are cross-linked (e.g., partially merged) to form the saddle-shaped lens. In some examples, the cross-link (or saddle-shaped lens) may be formed using one or more of thermal reflow, replicating, patterning, or imprinting processes performed at the wafer level. For purposes of this description, “light” is defined as any form of electromagnetic radiation and includes visible and invisible light. 
     Saddle-shaped lenses formed as described herein may be used to provide high aspect ratio illumination, with an optical element that is very small, that is integrated with a light source and/or positioned very close to (e.g., on) the aperture of a light source. This can reduce the stack-up height for a light source and its lens. The high aspect ratio beam shaping provided by a saddle-shaped lens also increases the divergence of a beam of light emitted by a laser or similar spot-like light source, thereby distributing the light source&#39;s optical power over a larger field of view and changing a device&#39;s eye safety class to improve the device&#39;s eye safety. Saddle-shaped lenses formed as described herein may also provide a lens per light source, whereas separately formed optical elements can be bulky, and may need to be positioned over more than one light source. This can compromise the beam-shaping ability per light source. A separate optical element attached to a light source may also be more prone to becoming dislodged from its light source(s). 
     Forming a saddle-shaped lens at the wafer level also reduces alignment errors, as the components used to form the saddle-shaped lens can be positioned very precisely with respect to a light source at the wafer level. 
     In some embodiments, a light-emitting device may include a semiconductor substrate, a surface-emitting semiconductor light source on the semiconductor substrate, a monolithic first dielectric, and a second dielectric. The monolithic first dielectric may be transparent to light emitted by the light source and include first and second micro-lenses and a saddle-shaped lens. The first and second micro-lenses may be adjacent an aperture of the light source and have axes parallel to and offset from an axis of a beam of light emitted by the light source. The saddle-shaped lens may be disposed over the aperture of the light source. The saddle-shaped lens may connect the first and second micro-lenses and reshape the beam of light emitted by the light source to have a high aspect ratio. The second dielectric may be transparent to light emitted by the light source, and may encapsulate a light emission surface of the saddle-shaped lens. The second dielectric may have a higher refractive index than the monolithic first dielectric. 
     These and other embodiments are discussed with reference to  FIGS. 1-13 . However, those skilled in the art will readily appreciate that the detailed description given herein with respect to these figures is for explanatory purposes only and should not be construed as limiting. 
       FIG. 1A  shows an example of a smart phone  100  having a camera  102 . By way of example,  FIG. 1A  shows a backside of the smart phone  100 , and the camera  102  is shown to be a rear-facing camera. In other embodiments, the camera  102  could be positioned on the frontside of the smart phone  100 , or the smart phone  100  could also have a front-facing camera. 
     The smart phone  100  has a light source  104  positioned adjacent the camera  102 . In alternate embodiments, the light source  104  could be positioned closer to the camera  102  or more distant from the camera  102 . When the camera is used in low light settings, the light source  104  may be flashed to illuminate an object or scene imaged by the camera  102 . If the camera  102  is capable of recording video, the light source  104  may be turned ON to provide steady-state illumination. In some cases, the light source  104  may be turned ON and operated as a flashlight. 
     When capturing a panoramic photo or video, or when needing high aspect ratio illumination (e.g., to light a sidewalk), it may be useful to have a light source that emits a beam of light having a high aspect ratio  106 . The light source  104  may therefore include one or more of the light-emitting devices described herein. In some cases, the light source  104  may include a high aspect ratio light-emitting device in addition to (or in some cases, instead of) a light-emitting device that provides spot or flood-type illumination. 
     In alternative embodiments, the camera  102  and light source  104  may be included in a camera device, a tablet computer, a laptop computer, or other electronic device or system. 
       FIG. 1B  shows an example of an electronic device  110  having a bioauthentication sensor  112 . In some examples, the electronic device  110  may be a smart phone having a display  116 , and in some embodiments, the electronic device  110  may be the smart phone  100  described with reference to  FIG. 1 . In these examples, the view shown in  FIG. 1B  may be the front side of the smart phone  100 . 
     The bioauthentication sensor  112  may include or be associated with a light source  114  that emits visible or invisible light (i.e., electromagnetic radiation). The visible or invisible light (e.g., infrared (IR) light) may be emitted to illuminate a body part that is to be scanned or imaged by the bioauthentication sensor  112 . In some examples, the bioauthentication sensor  112  may include a facial feature scanning camera. In some examples, the bioauthentication sensor  112  may include a fingerprint sensor, and the light source  114  may be positioned under or adjacent the fingerprint sensor. 
     When scanning a body part (e.g., a face, eye, finger, limb, etc.) of a user, it may be useful to have a light source that emits a beam of light having a high aspect ratio  118 . The light source  114  may therefore include one or more of the light-emitting devices described herein. In some cases, the light source  114  may include a high aspect ratio light-emitting device in addition to (or in some cases, instead of) a light-emitting device that provides spot or flood-type illumination. 
     In alternative embodiments, the bioauthentication sensor  112  and light source  114  may be included in a camera device, a tablet computer, a laptop computer, or other electronic device or system. 
       FIG. 1C  shows an example of a device having a navigation system  120 . By way of example, the navigation system  120  may include a scanning depth sensor  122 . One type of navigation system  120  that includes a scanning depth sensor  122  is a light detection and ranging (LIDAR) system. The scanning depth sensor  122  may include a SPAD array  124 . In other embodiments, the navigation system  120  may include another type of sensor, or an array of light-sensing pixels other than the SPAD array  124 . 
     The navigation system  120  may perform a line-scan operation to detect the presence of an object and determine a range to the object. In addition to the SPAD array  124 , the scanning depth sensor  122  may include a light-emitting device  126 , which may emit visible or invisible light. The light-emitting device  126  may emit a sequence of light pulses, separated by time periods during which no light is emitted. The time period between each light pulse may be referred to as a pulse repetition interval (PRI). In some cases, it can be useful for the light-emitting device  126  to emit a beam of light having a high aspect ratio  128 . 
     The beam of light  128  may be emitted into a FoV  130  and illuminate a section (e.g., a line) of the FoV  130 . The beam of light  128  may be steerable (e.g., up or down) within the FoV  130 . 
     Emitted light that reflects or is otherwise redirected from an object and/or a scene in the FoV  130  may be received by a lens  132  that directs the light onto the SPAD array  124 . In some embodiments, a processor associated with the navigation system  120  may compute time-of-flight times for pulses of light emitted into the FoV  130 . 
     In some examples, the navigation system  120  may be implemented as one or more components of a navigation system included in a motor vehicle. 
       FIG. 1D  shows an example of an electronic device  140  having a light source  142  for transmitting optical communications to a host device  144 . In some examples, the electronic device  140  may be a remote control device (or smart phone or other device operating as a remote control device). 
     The electronic device  140  may be spatially discovered by, authenticated by, tracked by, and communicate with the host device  144  by transmitting optical communications using the light source  142 . The optical communications may be received by a photodetector or other sensor  146  on the host device  144 . In some environments or applications, it may be useful for the electronic device  140  to transmit optical communications in one or multiple beams of light having a high aspect ratio  148 , which beams of light may be fixed or scanning. 
       FIG. 2  shows a first example of a light-emitting device  200  including a surface-emitting semiconductor light source  202  (e.g., a VCSEL, VECSEL, OLED, RC-LED, mLED, or SLED). The light-emitting device  200  may be used in any of the light sources described with reference to  FIGS. 1A-1D . The light source  202  may be formed on a semiconductor substrate  204  (e.g., a semiconductor die diced from a semiconductor wafer). 
     A pair of micro-lenses  206   a ,  206   b  may be formed adjacent an aperture of the light source  202 . By way of example, the pair of micro-lenses  206   a ,  206   b  may include a first micro-lens  206   a  and a second micro-lens  206   b . Axes  208   a ,  208   b  of the first and second micro-lenses  206   a ,  206   b  may be parallel to and offset from an axis  210  of a beam of light emitted by the light source  202 . A saddle-shaped lens  212  connects the first and second micro-lenses  206   a ,  206   b  and is positioned over the aperture of the light source  202 . The saddle-shaped lens  212  may have different contours/curvatures in orthogonal directions, and may reshape a beam of light emitted by the light source  202  to have a high aspect ratio. In some embodiments, the beam of light emitted by the light source  202  may have a generally circular and symmetrical cross-section, and the saddle-shaped lens  212  may reshape (i.e., alter the shape) of the beam&#39;s cross-section to have a high aspect ratio. A beam of light having a high aspect ratio is defined herein to be a beam of light having a cross-section with first and second perpendicular (or substantially perpendicular) diameters, with the first diameter being smaller than the second diameter. A beam of light having a high aspect ratio is also defined herein to be a beam of light that diverges at a greater angle (or has a wider FoV) in a first plane including the axis  210  of the beam of light (e.g., in one direction) than in a second plane including the axis  210  of the beam of light (e.g., in another direction), with the first plane or first direction being perpendicular (or substantially perpendicular) to the second plane or second direction. 
     The saddle-shaped lens  212  may have a height (H) and a width (W) at a center of its length (L), with the length (L) being greater than the width (W). The saddle-shaped lens  212  may have a highly anamorphic saddle shape along its ridge, which shape may be controlled by photo mask design and thermal reflow process parameters when performing wafer processing methods such as those described with reference to  FIGS. 5-8 . In some embodiments, the pair of micro-lenses  206   a ,  206   b  may be connected not only by the saddle-shaped lens  212 , but by flatter portions of a dielectric that forms the micro-lenses  206   a ,  206   b  and saddle-shaped lens  212 . The light emission surfaces of the saddle-shaped lens  212  may contact the semiconductor substrate  204  or a layer thereon (e.g., the flatter portion of the dielectric that forms the micro-lenses  206   a ,  206   b  and saddle-shaped lens  212 ), at e.g. a slope angle equal to or larger than 40 degrees. 
     The pair of micro-lenses  206   a ,  206   b  and saddle-shaped lens  212  may form a monolithic first dielectric  214 . The first dielectric  214  may be transparent to light emitted by the light source  202  (e.g., transparent to one or more, or all, wavelengths of light emitted by the light source  202 ). In some embodiments, the light source  202  may emit coherent light having only a single wavelength. 
     A second dielectric  216 , having a higher refractive index than the monolithic first dielectric  214 , may encapsulate a light emission surface of the saddle-shaped lens  212 . In some examples, the refractive index of the second dielectric  216  may be more than 0.2 times larger than (or more than 20 percent (20%) higher than) the refractive index of the monolithic first dielectric  214 ). The second dielectric  216  may be transparent to light emitted by the light source  202  (e.g., transparent to one or more, or all, wavelengths of light emitted by the light source  202 ), and may prevent light emitted by the light source  202  from experiencing total internal reflection within the saddle-shaped lens  212 . Total internal reflection may occur, absent the second dielectric  216 , because of the steep curvature of the saddle-shaped lens  212 . In some embodiments, the second dielectric  216  may cover all surfaces of the monolithic first dielectric  214  other than a surface (or surfaces) of the first monolithic dielectric that abuts the semiconductor substrate  204  or flatter portion of the dielectric that forms the saddle-shaped lens  212  and micro-lenses  206   a ,  206   b . The second dielectric  216  may have a light emission surface  218  parallel to a surface  220  of the semiconductor substrate  204  that contains the aperture of the light source  202  (i.e., parallel to an aperture-containing surface  220  of the semiconductor substrate  204 ). The second dielectric  216  may facilitate low-loss beam bending and provide surface passivation/protection. The combination of the saddle-shaped lens  212  and second dielectric  216  having higher refractive index provides a moderate positive optical power along the ridge of the saddle-shaped lens  212 , which tends to collimate (decrease) the divergence of the light beam emitted by the light source  202 . The combination of saddle-shaped lens  212  and second dielectric  216  also provides a strong negative optical power across the ridge of the saddle-shaped lens  212 , which tends to increase the divergence of the light beam emitted by the light source  202 . 
     In some embodiments of the light-emitting device  200 , the micro-lenses  206   a ,  206   b  may be replaced with other dielectric features. In some embodiments, the micro-lenses  206   a ,  206   b  or other dielectric features may partially or wholly removed when the light-emitting device  200  is diced from a semiconductor wafer. 
       FIG. 3A  shows a second example of a light-emitting device  300  including a surface-emitting semiconductor light source  202 . The light-emitting device  300  may be used in any of the light sources described with reference to  FIGS. 1A-1D . The light-emitting device  300  may be similar in most respects to the light-emitting device  200  described with reference to  FIG. 2 , but may have a saddle-shaped lens  212   a  with a height (H 2 ) and width (W 2 ) at a center of its length (L 2 ), with the length (L 2 ) being greater than the width (W 2 ). The height H 2  of the saddle-shaped lens  212   a  may be greater than the height H of the saddle-shaped lens  212 . The higher height of the saddle-shaped lens  212   a  may enable the saddle-shaped lens  212   a  to reshape a beam of light emitted by the light source  202  to have a higher aspect ratio than the beam of light emitted from the saddle-shaped lens  212 . 
     In  FIG. 3A , the saddle-shaped lens  212   a  is shown to have an axis  210   a  that is distinct from the axis  210  of the beam of light emitted by the light source  202 . In some embodiments, the saddle-shaped lens  212   a  may be formed such that the axis  210   a  is offset from the axis  210 . In this manner, the saddle-shaped lens  212   a  may not only reshape the beam of light to have a high aspect ratio, but may also bend the beam of light (e.g., change its direction). 
       FIG. 3B  shows a cross-section of the light-emitting device  300  shown in  FIG. 3A . As shown, the saddle-shaped lens  212   a  is disposed over an aperture  302  of a light source  202 . The aperture  302  of the light source  202  may be disposed adjacent a contact  304   a , or between a pair of contacts  304   a ,  304   b . All of the structures shown in  FIGS. 3A &amp; 3B  may be formed using wafer processing techniques, as described for example with reference to  FIGS. 5, 6A-6H, 7, and 8A-8I . 
       FIG. 3C  shows a divergence  310  of light emitted across the width (W 2 ) of the saddle-shaped lens  212   a  shown in  FIGS. 3A and 3B .  FIG. 3D  shows a divergence  320  of light emitted across the length (L 2 ) of the saddle-shaped lens  212   a  shown in  FIGS. 3A and 3B .  FIGS. 3C and 3D  illustrate the reshaping of a beam of light  312  by the saddle-shaped lens  212   a , and illustrate the high aspect ratio of the beam of light  312  after it exits the saddle-shaped lens  212   a . The beam of light  312  may further diverge in at least the direction of its width (W 2 ) as it leaves the second dielectric  216 . In some embodiments, the saddle-shaped lens  212   a  and second dielectric  216  may reshape a beam of light  312  emitted by the light source  202  to have a beam divergence of greater than or equal to 120 degrees in a first plane including the axis  210  of the beam of light  312  (as shown in  FIG. 3C ), and less than or equal to 20 degrees in a second plane including the axis  210  of the beam of light  312  (e.g., in a second plane perpendicular (or substantially perpendicular) to the first plane, as shown in  FIG. 3D ). 
       FIG. 4A  illustrates far field illumination  400  provided by the light-emitting device  300  described with reference to  FIG. 3A , in an angular space. In particular,  FIG. 4A  shows the relationship between radiance in the angular space in relation to an angle (in degrees) of beam divergence.  FIG. 4B  illustrates far field illumination  410  provided by the light-emitting device  300  described with reference to  FIG. 3A , in a position space. In particular,  FIG. 4B  shows the relationship between incoherent irradiance in the position space and an angle (in degrees) of beam divergence. 
       FIG. 5  shows a first example of a method  500  for making a plurality of light-emitting devices, including, for example, the light-emitting device described with reference to  FIG. 2 or 3A . The light-emitting devices are formed on a wafer, using wafer processing techniques.  FIGS. 6A-6H  show example cross-sections of various interim forms of the light-emitting devices, which interim forms of the light-emitting device may exist after performing the operation(s) included in various blocks of the method  500 . 
     At block  502 , and with reference to  FIG. 6A , the method  500  may include forming a plurality of surface-emitting semiconductor light sources  602  on a semiconductor wafer  604 . The semiconductor light sources  602  may include, for example, VCSELs, VECSELs, OLEDs, RC-LEDs, mLEDs, or SLEDs. In some embodiments, formation of the light sources  602  may include (or conclude with) forming and patterning an electrically conductive top-side layer  606  (e.g., a gold (Au) layer). The top-side gold layer  606  may include contacts for driving the light sources  602 . The contacts may be formed adjacent (e.g., to the side of) light-emitting apertures  608  of the light sources  602 . 
     At block  504 , and with reference to  FIG. 6B , the method  500  may include depositing a first dielectric layer  610 . In some cases, the first dielectric layer  610  may be deposited over an entirety of the top side (i.e., the light-emitting side) of the device shown in  FIG. 6A . In some embodiments, the first dielectric layer  610  may be formed using a polymer or crystalline dielectric. As will be described with reference to later blocks, micro-lenses (e.g., a micro-lens array (MLA)) and saddle-shaped lenses may be formed in the first dielectric layer  610 . Also at block  504 , a photoresist (PR) layer  612  may be deposited on top of the first dielectric layer  610 . 
     At block  506 , and with reference to  FIG. 6C , the method  500  may including placing a mask  614  over the PR layer  612 , and exposing the exposed portions of the PR layer  612  to radiation  616  (e.g., thermal or optical radiation). 
     At block  508 , and with reference to  FIG. 6D , the method  500  may include etching the PR layer  612  to remove portions of the PR layer  612  that were exposed to radiation  616  at block  506 . The etching may form a PR layer having a plurality of islands of PR material  612   a , with the islands of PR material  612   a  positioned on opposite sides of the apertures  608  of the light sources  602 . Although a positive PR material is described, the method  500  could alternately be modified to operate with a negative PR material. 
     At block  510 , and with reference to  FIG. 6E , the method  500  may include subjecting the device to a thermal reflow process that causes the islands of PR material  612   a  to reflow. The reflow causes the edges of each island of PR material  612   a  to collapse, and causes the perimeter of each island of PR material  612   a  to enlarge such that adjacent islands of PR material  612   a  join at a plurality of cross-link features  618 . The islands of PR material  612   a  are left with slumped or convex edges that join at the cross-link features  618 . 
     At block  512 , and with reference to  FIG. 6F , the method  500  may include replicating the top-side contour of the PR layer  612  to the dielectric layer  610 . This produces a plurality of micro-lenses  620  joined by saddle-shaped lenses  622 . The micro-lenses  620  are adjacent the apertures  608  of the light sources  602 , and the saddle-shaped lenses  622  are over (e.g., aligned with) the apertures  608 . 
     At block  514 , and with reference to  FIG. 6G , the method  500  may include depositing a second dielectric layer  624  on the first dielectric layer  610 . The second dielectric layer  624  may have a higher refractive index than the first dielectric layer  610 . In some embodiments, the second dielectric layer  624  may be formed using a polymer or crystalline dielectric. In some embodiments, the second dielectric layer  624  may be polished or reflowed to flatten the top-side surface  626  of the second dielectric layer  624 . An anti-reflective (AR) coating may optionally be deposited on the second dielectric layer  624 . 
     At block  516 , and with reference to  FIG. 6H , the method  500  may include a continuation of wafer processing, with an epi-thinning operation, back-side metal plating operation, or other operations. 
     In some embodiments of the method  500 , one or more additional thermal reflow processes (or other processes) may be performed to introduce wafer-level optics components into the second dielectric layer  624  or other layers. 
       FIG. 7  shows a second example of a method  700  for making a plurality of light-emitting devices, including, for example, the light-emitting device described with reference to  FIG. 2 or 3A . The light-emitting devices are formed on a wafer, using wafer-processing techniques.  FIGS. 8A-8E  show example cross-sections of a device used to make the light-emitting devices, and  FIGS. 8F-8I  show example cross-sections of various interim forms of the light-emitting devices, which interim forms of the light-emitting device may exist after performing the operation(s) included in various blocks of the method  700 . 
     In blocks  702 - 710 , a master patterning device  812  is formed. The master patterning device may be formed on a semiconductor wafer  802  (or, for example, a dielectric substrate, or a metal substrate). At block  702 , and with reference to  FIG. 8A , the method  700  may include depositing a PR layer  804  on the semiconductor wafer  802 . 
     At block  704 , and with reference to  FIG. 8B , the method  700  may include placing a mask  806  over the PR layer  804 , and exposing the PR layer  804  to radiation  808  (e.g., thermal or optical radiation). 
     At block  706 , and with reference to  FIG. 8C , the method  700  may include etching the PR layer  804  to remove portions of the PR layer  804  that were exposed to radiation  808  at block  704 . The etching may form a PR layer having a plurality of islands of PR material  804   a , with the islands of PR material  804   a . Although a positive PR material is described, the method  700  could alternately be modified to operate with a negative PR material. 
     At block  708 , and with reference to  FIG. 8D , the method  700  may include subjecting the device to a thermal reflow process that causes the islands of PR material  804   a  to reflow. The reflow causes the edges of each island of PR material  804   a  to collapse, and causes the perimeter of each island of PR material  804   a  to enlarge such that adjacent islands of PR material  804   a  join at a plurality of cross-link features  810 . The islands of PR material  804   a  are left with slumped or convex edges that join at the cross-link features  810 . 
     At block  710 , and with reference to  FIG. 8E , the method  700  may include replicating the top-side contour of the PR layer  804  to the semiconductor wafer  802 . This produces the master patterning device  812 , which may have a top-side contour that is the compliment of the contour of micro-lenses and saddle-shaped lenses desired in a light-emitting device. 
     At block  712 , and with reference to  FIG. 8F , the method  700  may include forming a plurality of surface-emitting semiconductor light sources  814  on a semiconductor wafer  816  (i.e., on a second semiconductor wafer). The semiconductor light sources  814  may include, for example, VCSELs, VECSELs, OLEDs, RC-LEDs, mLEDs, or SLEDs. In some embodiments, formation of the light sources  814  may include (or conclude with) forming and patterning an electrically conductive top-side layer  818  (e.g., a gold (Au)). The top-side gold layer  818  may include contacts for driving the light sources  814 . The contacts may be formed adjacent (e.g., to the side of) light-emitting apertures  820  of the light sources  814 . 
     Also at block  712 , the method  700  may include depositing a first dielectric layer  822 . In some cases, the first dielectric layer  822  may be deposited over an entirety of the top side (i.e., the light-emitting side) of the semiconductor wafer  816 . In some embodiments, the first dielectric layer  822  may be formed using a polymer or crystalline dielectric. As will be described with reference to later blocks, micro-lenses (e.g., an MLA) and saddle-shaped lenses may be formed in the first dielectric layer  822 . 
     At block  714 , and with reference to  FIG. 8G , the method  700  may include imprinting (e.g., negatively imprinting) the shaped contour of the master patterning  812  device into the first dielectric layer  822 . This produces a plurality of micro-lenses  824  joined by saddle-shaped lenses  826 . The micro-lenses  824  are adjacent the apertures  820  of the light sources  814 , and the saddle-shaped lenses  826  are over (e.g., aligned with) the apertures  820 . 
     At block  716 , and with reference to  FIG. 8H , the method  700  may include curing the first dielectric layer  822 . 
     At block  718 , and with reference to  FIG. 8I , the method  700  may include depositing a second dielectric layer  828  on the first dielectric layer  822 . The second dielectric layer  828  may have a higher refractive index than the first dielectric layer  822 . In some embodiments, the second dielectric layer  828  may be formed using a polymer or crystalline dielectric. In some embodiments, the second dielectric layer  828  may be polished or reflowed to flatten the top-side surface  830  of the second dielectric layer  828 . An AR coating may optionally be deposited on the second dielectric layer  828 . 
     At block  720 , the method  700  may include a continuation of wafer processing, with an epi-thinning operation, back-side metal plating operation, or other operations. 
     In some embodiments of the method  700 , one or more additional patterning or thermal reflow processes (or other processes) may be performed to introduce wafer-level optics components into the second dielectric layer  828  or other layers. 
     In each of the methods  500  and  700 , a saddle-shaped lens  622  or  826  is formed on a functional surface-emitting semiconductor light source  602  or  814  epi structure using wafer-level processing steps such as the etching and thermal reflow of a PR layer to produce thermally reflowed and cross-linked islands of PR material. 
       FIGS. 9 and 10  show light-emitting devices including a set of light sources (e.g., a set of surface-emitting semiconductor light sources). 
       FIG. 9  shows a light-emitting device  900  having two light sources  902 ,  904  (e.g., two surface-emitting semiconductor light sources). The light-emitting device  900  may be used as a light source in any of the devices described with reference to  FIGS. 1A-1D . The two light sources  902 ,  904  may be formed on a set of one or more semiconductor substrates (e.g., one or more semiconductor die diced from a semiconductor wafer). For example, the light sources  902 ,  904  may be formed on a common semiconductor die  906 , or the light sources  902 ,  904  may be formed on different semiconductor die (e.g., different semiconductor die diced from the same or different semiconductor wafers) and mounted in close proximity to one another on an additional semiconductor or other substrate. 
     A first saddle-shaped lens  908  may extend between a first pair of micro-lenses (e.g., a first micro-lens  910  and a second micro-lens  912 ) and be positioned over a first aperture of the first light source  902 . A second saddle-shaped lens  914  may extend between a second pair of micro-lenses (e.g., a third micro-lens  916  and a fourth micro-lens  918 ) and be positioned over a second aperture of the second light source  904 . Alternatively, the different pairs of micro-lenses may share a micro-lens, thereby eliminating a micro-lens (e.g., the first saddle-shaped lens  908  may extend between first and second micro-lenses, and the second saddle-shaped lens  914  may extend between the second micro-lens and a third micro-lens). In the latter case, the micro-lenses and saddle-shaped lenses  908 ,  914  may form a monolithic dielectric. 
     Each saddle-shaped lens  908 ,  914  may have different contours/curvatures in orthogonal directions, and may reshape a beam of light emitted by one of the light sources  902 ,  904  to have a high aspect ratio. In some embodiments, the saddle-shaped lenses  908 ,  914  may have different angular orientations. That is, a first axis  920  oriented along a length of the first saddle-shaped lens  908  may intersect a second axis  922  oriented along a length of the second saddle-shaped lens  914  (not shown). The first and second axes  920 ,  922  may be perpendicular to one another, or may intersect at an angle other than a right angle. In some embodiments, the first and second saddle lenses  908 ,  914  may be de-centered along the axes  920 ,  922  by different amounts from their corresponding emitter apertures  902 ,  904 , to steer their respective high-aspect ratio beams in their low divergence/collimated directions to occupy/stitch different far field spaces. 
     Each of the micro-lenses  910 ,  912 ,  916 ,  918  and saddle-shaped lenses  908 ,  914  may be formed from a dielectric that is transparent to light emitted by the first and second light sources  902 ,  904  (e.g., transparent to one or more, or all, wavelengths of light emitted by the light sources  902 ,  904 ). In some embodiments, each light source  902 ,  904  may emit coherent light having only a single wavelength. A second dielectric  924  may encapsulate each of the saddle-shaped lenses  908 ,  914 . The second dielectric  924  may have a higher refractive index than the dielectric from which the micro-lenses  910 ,  912 ,  916 ,  918  and saddle-shaped lenses  908 ,  914  are formed, and may encapsulate the light emission surfaces of the saddle-shaped lenses  908 ,  914 . In some embodiments, the second dielectric  924  may also encapsulate the micro-lenses  910 ,  912 ,  916 ,  918 . The second dielectric  924  may also be transparent to light emitted by the light sources  902 ,  904  (e.g., transparent to one or more, or all, wavelengths of light emitted by the light sources  902 ,  904 ), and may prevent light emitted by the light sources  902 ,  904  from experiencing total internal reflection within the saddle-shaped lenses  908 ,  914 . The second dielectric  924  may have a light emission surface  926  parallel to the surface of the semiconductor die  906  that contains the apertures of the light sources  902 ,  904  (i.e., parallel to an aperture-containing surface of the semiconductor die  906 ). 
     In some embodiments, each of the micro-lenses  910 ,  912 ,  916 ,  918  and saddle-shaped lenses  908 ,  914  may be formed using a same first dielectric, and encapsulated using a same second dielectric  924 . In other embodiments, different pairs of micro-lenses and the saddle-shaped lens that connects them may be formed of different dielectrics and/or different pairs of micro-lenses and the saddle-shaped lens that connects them may be encapsulated by different dielectrics. 
     In some embodiments, the saddle-shaped lenses  908 ,  914  may have the same aspect ratio. In other embodiments, the saddle-shaped lenses  908 ,  914  may have different aspect ratios. The light sources  902 ,  904  may emit the same or different wavelengths (or colors) of light, or emit the same or different type of electromagnetic radiation. 
     A controller may turn the light sources  902 ,  904  on and off (i.e., activate and deactivate the light sources) alternately, sequentially, or simultaneously. To enable the light sources  902 ,  904  to be turned on and off alternately or sequentially, the drive circuits and electrical contacts for the light sources  902 ,  904  may be configured to be individually addressable. When the light sources  902 ,  904  are positioned in close proximity to one another and turned on and off at different times, in an alternating manner (e.g., when the first light source  902  is turned on while the second light source  904  is off, then the second light source  904  is turned on while the first light source  902  is off), the beams of light emitted by the light sources  902 ,  904  may simulate a single, rotating, high aspect ratio, beam of light at a far field. 
     Alternatively, when the light sources  902 ,  904  are positioned in close proximity to one another, a selected one of the light sources  902 ,  904  may be turned on to angularly tune an orientation of a single, high aspect ratio, beam of light at a far field (e.g., to provide on-demand/angularly tunable high aspect ratio illumination). 
     In some embodiments, the set of beams emitted by the light sources  902 ,  904  may be received and shaped by a same optical element (or set of optical elements) in a near field. For example, the set of beams may be received and shaped by a cone lens. 
     When a plurality of light-emitting devices are constructed as described with reference to  FIG. 9 , and the light-emitting devices are mounted in an array, the light-emitting devices may be operated (e.g., by a controller) in the same or different manners. 
       FIG. 10  shows a light-emitting device  1000  having three light sources  1002 ,  1004 ,  1006  (e.g., three surface-emitting semiconductor light sources). The light-emitting device  1000  may be used as a light source in any of the devices described with reference to  FIGS. 1A-1D . The three light sources  1002 ,  1004 ,  1006  may be formed on a set of one or more semiconductor substrates (e.g., one or more semiconductor die diced from a semiconductor wafer). For example, the light sources  1002 ,  1004 ,  1006  may be formed on a common semiconductor die  1008 , or the light sources  1002 ,  1004 ,  1006  may be formed on different semiconductor die (e.g., different semiconductor die diced from the same or different semiconductor wafers) and mounted in close proximity to one another on an additional semiconductor or other substrate. 
     A first saddle-shaped lens  1010  may extend between a first pair of micro-lenses (e.g., a first micro-lens  1012  and a second micro-lens  1014 ) and be positioned over a first aperture of the first light source  1002 . A second saddle-shaped lens  1016  may extend between a second pair of micro-lenses (e.g., the second micro-lens  1014  and a third micro-lens  1018 ) and be positioned over a second aperture of the second light source  1004 . A third saddle-shaped lens  1020  may extend between a third pair of micro-lenses (e.g., the first micro-lens  1012  and the third micro-lens  1018 ) and be positioned over a third aperture of the third light source  1006 . As shown, the micro-lenses  1012 ,  1014 ,  1018  and saddle-shaped lenses  1010 ,  1016 ,  1020  may form a monolithic dielectric. Alternatively, two or more pairs of the micro-lenses may not share a micro-lens (e.g., the first saddle-shaped lens may extend between first and second micro-lenses, the second saddle-shaped lens may extend between third and fourth micro-lenses, and the third saddle-shaped lens may extend between fifth and sixth micro-lenses). 
     Each saddle-shaped lens  1010 ,  1016 ,  1020  may be constructed similarly to one of the saddle-shaped lenses described with reference to  FIG. 9 , and may have a different angular orientation than the other saddle-shaped lenses  1010 ,  1016 ,  1020 . That is, a first axis  1022  oriented along a length of the first saddle-shaped lens  1010  may intersect a second axis  1024  oriented along a length of the second saddle-shaped lens  1016 , and a third axis  1026  oriented along a length of the third saddle-shaped lens  1020  may intersect both the first axis  1022  and the second axis  1024 . Each of the saddle-shaped lenses  1010 ,  1016 ,  1020  may reshape a beam of light to have a greatest divergence along its width. In some embodiments, each of the first, second, and third axes  1022 ,  1024 ,  1026  may be rotated 60 degrees with respect to each of the other axes  1022 ,  1024 ,  1026  (e.g., each of the axes  1022 ,  1024 ,  1026  may define a different side of an equilateral triangle). Alternatively, the first, second, and third axes  1022 ,  1024 ,  1026  may intersect each other at other angles (e.g., the light sources  1002 ,  1004 ,  1006  and saddle-shaped lenses  1010 ,  1016 ,  1020  may be positioned along edges of a hexagon or other shape. Alternatively, one or more of the light sources  1002 ,  1004 ,  1006  may be offset from the axis  1022 ,  1024 , of  1026  of its saddle-shaped lens  1010 ,  1016 , or  1020 . 
     Each of the micro-lenses  1012 ,  1014 ,  1018  and saddle-shaped lenses  1010 ,  1016 ,  1020  may be formed from a dielectric that is transparent to light emitted by the first, second, and third light sources  1002 ,  1004 ,  1006  (e.g., transparent to one or more, or all, wavelengths of light emitted by the light sources  1002 ,  1004 ,  1006 ). In some embodiments, each light source  1002 ,  1004 ,  1006  may emit coherent light having only a single wavelength. A second dielectric  1028  may encapsulate each of the saddle-shaped lenses  1010 ,  1016 ,  1020 . The second dielectric  1028  may have a higher refractive index than the dielectric from which the micro-lenses  1012 ,  1014 ,  1018  and saddle-shaped lenses  1010 ,  1016 ,  1020  are formed, and may encapsulate the light emission surfaces of the saddle-shaped lenses  1010 ,  1016 ,  1020 . In some embodiments, the second dielectric  1028  may also encapsulate the micro-lenses  1012 ,  1014 ,  1018 . The second dielectric  1028  may also be transparent to light emitted by the light sources  1002 ,  1004 ,  1006  (e.g., transparent to one or more, or all, wavelengths of light emitted by the light sources  1002 ,  1004 ,  1006 ), and may prevent light emitted by the light sources  1002 ,  1004 ,  1006  from experiencing total internal reflection within the saddle-shaped lenses  1010 ,  1016 ,  1020 . The second dielectric  1028  may have a light emission surface  1030  parallel to the surface of the semiconductor die  1008  that contains the apertures of the light sources  1002 ,  1004 ,  1006  (i.e., parallel to an aperture-containing surface of the semiconductor die  1008 ). 
     In some embodiments, the saddle-shaped lenses  1010 ,  1016 ,  1020  may have the same aspect ratio. In other embodiments, the saddle-shaped lenses  1010 ,  1016 ,  1020  may have different aspect ratios. The light sources  1002 ,  1004 ,  1006  may emit the same or different wavelengths (or colors) of light, or emit the same or different type of electromagnetic radiation. 
     A controller may turn the light sources  1002 ,  1004 ,  1006  on and off (i.e., activate and deactivate the light sources  1002 ,  1004 ,  1006 ) alternately, sequentially, or simultaneously. To enable the light sources  1002 ,  1004 ,  1006  to be turned on and off alternately or sequentially, the drive circuits for the light sources  1002 ,  1004 ,  1006  may be configured to be individually addressable. When the light sources  1002 ,  1004 ,  1006  are positioned in close proximity to one another and turned on and off at different times, in an alternating manner (e.g., when the first light source  1002  is turned on while the second and third light sources  1004 ,  1006  are off, then the second light source  1004  is turned on while the first and third light sources  1002 ,  1006  are off, then the third light source  1006  is turned on while the first and second light sources  1002 ,  1004  are off), the beams of light emitted by the light sources  1002 ,  1004 ,  1006  may simulate a single, rotating, high aspect ratio, beam of light at a far field. 
     Alternatively, when the light sources  1002 ,  1004 ,  1006  are positioned in close proximity to one another, a selected one of the light sources  1002 ,  1004 ,  1006  may be turned on to angularly tune an orientation of a single, high aspect ratio, beam of light at a far field (e.g., to provide on-demand/angularly tunable high aspect ratio illumination). 
     In some embodiments, the set of beams emitted by the light sources  1002 ,  1004 ,  1006  may be received and shaped by a same optical element (or set of optical elements) in a near field. For example, the set of beams may be received and shaped by a cone lens. 
     When a plurality of light-emitting devices are constructed as described with reference to  FIG. 10 , and the light-emitting devices are mounted in an array, the light-emitting devices may be operated (e.g., by a controller) in the same or different manners. 
       FIGS. 11A-11C  depict an illumination provided by the light-emitting device  1000  described with reference to  FIG. 10 , in a far-field plane  1100 , when the light sources  1002 ,  1004 ,  1006  are positioned in close proximity to one another and turned on and off at different times, in an alternating manner.  FIG. 11A  illustrates the illumination  1110  provided by the light-emitting device  1000 , in the far-field plane  1100 , when only the first light source  1002  is turned on.  FIG. 11B  illustrates the illumination  1120  provided by the light-emitting device  1000 , in the far-field plane  1100 , when only the second light source  1004  is turned on.  FIG. 11C  illustrates the illumination  1130  provided by the light-emitting device  1000 , in the far-field plane  1100 , when only the third light source  1006  is turned on.  FIG. 11D  illustrates a panorama  1140  of the illumination provided by the light-emitting device  1000 , and an element such as a panoramic optical lens  1142  or mirror that converts the angular rotation of the beams of light emitted from the saddle-shaped lenses  1010 ,  1016 ,  1020  to a panoramic projection. The light-emitting device  1000  may be referred to, in some embodiments, as a panoramic beam scanner when operated as described with reference to  FIGS. 11A-11D . 
       FIGS. 12A and 12B  depict an illumination provided by the light-emitting device  1000  described with reference to  FIG. 10 , in different far-field planes  1200 ,  1204 , when the light sources  1002 ,  1004 ,  1006  are positioned in close proximity to one another and turned on simultaneously. In some embodiments, the high aspect ratio near-field beam patterns of the light-emitting device  1000  are fed to an image optical system that projects the high aspect ratio near-field beam patterns into far-field space.  FIG. 12A  illustrates the illumination  1202  provided by the light-emitting device  1000  in a first far-field plane  1200  (e.g., in a far-field plane positioned 1 meter (m) from the light-emitting device  1000 ).  FIG. 12B  illustrates the illumination  1206  provided by the light-emitting device  1000  in a second far-field plane  1204  (e.g., in a far-field plane positioned 2 m from the light-emitting device), with the second far-field plane  1204  being farther from the light-emitting device  1000  than the first far-field plane  1200 . 
     The light shown in  FIGS. 12A and 12B  may be referred to as structured light. When a light-emitting device such as the light-emitting device  1000  emits structured light, it adds additional degrees-of-freedom (DOF) in both aspect ratio and orientation. For example, depending on the depth of field and aberration of a system including the light-emitting device  1000 , the structured light may be inherently encoded with depth information, which depth information can be determined from the size and shape of the structured light when projected on a particular far-field plane (e.g., far-field plane  1200  or  1204 ). The structured light is also inherently encoded with angular orientation information, because the shapes and sizes of the spots attributable to different light sources, and the relationships between the shapes and sizes, will change when the light-emitting device  1000  is oriented at different angles with respect to a far-field plane. Traditional structured light grid patterns have been arranged in spatial tiles of locally unique collections of pseudo-random positioning of identical isolated light beam spots. High resolution depth information was then retrieved by an imaging system capturing the disparity of spot positioning intercepted by a three-dimensional (3D) surface. The additional shape DOF shown in  FIGS. 12A and 12B  (orientation and aspect ratio of isolated brightness patterns) can facilitate faster and more reliable structured light capturing and higher resolution depth information retrieval. The light patterns shown in  FIGS. 12A and 12B  may be referred to as angular-variant high aspect ratio spatially structured light. 
       FIG. 13  shows a sample electrical block diagram of an electronic device  1300 , which electronic device may in some cases take the form of one of the devices described with reference to  FIGS. 1A-1D . The electronic device  1300  may include a display  1302  (e.g., a light-emitting display), a processor  1304 , a power source  1306 , a memory  1308  or storage device, a sensor system  1310 , an input/output (I/O) mechanism  1312  (e.g., an input/output device, input/output port, or haptic input/output interface), or a light source  1314 . The processor  1304  may control some or all of the operations of the electronic device  1300 . The processor  1304  may communicate, either directly or indirectly, with some or all of the other components of the electronic device  1300 . For example, a system bus or other communication mechanism  1316  can provide communication between the processor  1304 , the power source  1306 , the memory  1308 , the sensor system  1310 , the I/O mechanism  1312 , and the light source  1314 . 
     The processor  1304  may be implemented as any electronic device capable of processing, receiving, or transmitting data or instructions, whether such data or instructions is in the form of software or firmware or otherwise encoded. For example, the processor  1304  may include a microprocessor, a central processing unit (CPU), an application-specific integrated circuit (ASIC), a digital signal processor (DSP), a controller, or a combination of such devices. As described herein, the term “processor” is meant to encompass a single processor or processing unit, multiple processors, multiple processing units, or other suitably configured computing element or elements. In some embodiments, the processor  1304  may function as the controller described with reference to  FIG. 9 or 10 . 
     It should be noted that the components of the electronic device  1300  can be controlled by multiple processors. For example, select components of the electronic device  1300  (e.g., a sensor system  1310  or light source  1314 ) may be controlled by a first processor and other components of the electronic device  1300  (e.g., the display  1302 ) may be controlled by a second processor, where the first and second processors may or may not be in communication with each other. 
     The power source  1306  can be implemented with any device capable of providing energy to the electronic device  1300 . For example, the power source  1306  may include one or more batteries or rechargeable batteries. Additionally or alternatively, the power source  1306  may include a power connector or power cord that connects the electronic device  1300  to another power source, such as a wall outlet. 
     The memory  1308  may store electronic data that can be used by the electronic device  1300 . For example, the memory  1308  may store electrical data or content such as, for example, audio and video files, documents and applications, device settings and user preferences, timing signals, control signals, and data structures or databases. The memory  1308  may include any type of memory. By way of example only, the memory  1308  may include random access memory, read-only memory, Flash memory, removable memory, other types of storage elements, or combinations of such memory types. 
     The electronic device  1300  may also include one or more sensor systems  1310  positioned almost anywhere on the electronic device  1300 . The sensor system(s)  1310  may be configured to sense one or more type of parameters, such as but not limited to, pressure on the display  1302 , a crown, a button, or a housing of the electronic device  1300 ; light; touch; heat; movement; relative motion; biometric data (e.g., biological parameters) of a user; and so on. For example, the sensor system(s)  1310  may include a watch crown sensor system, a heat sensor, a position sensor, a light or optical sensor, an accelerometer, a pressure transducer, a gyroscope, a magnetometer, a health monitoring sensor, and so on. Additionally, the one or more sensor systems  1310  may utilize any suitable sensing technology, including, but not limited to, capacitive, ultrasonic, resistive, optical, ultrasound, piezoelectric, and thermal sensing technology. In some examples, the sensor system(s)  1310  may include one or more of the sensor systems described herein. 
     The I/O mechanism  1312  may transmit or receive data from a user or another electronic device. The I/O mechanism  1312  may include a display, a touch sensing input surface, a crown, one or more buttons (e.g., a graphical user interface “home” button), one or more cameras, one or more microphones or speakers, one or more ports such as a microphone port, and/or a keyboard. Additionally or alternatively, the I/O mechanism  1312  may transmit electronic signals via a communications network, such as a wireless and/or wired network connection. Examples of wireless and wired network connections include, but are not limited to, cellular, Wi-Fi, Bluetooth, IR, and Ethernet connections. 
     The light source  1314  may include any of the light-emitting devices described herein. 
     The foregoing description, for purposes of explanation, uses specific nomenclature to provide a thorough understanding of the described embodiments. However, it will be apparent to one skilled in the art, after reading this description, that the specific details are not required in order to practice the described embodiments. Thus, the foregoing descriptions of the specific embodiments described herein are presented for purposes of illustration and description. They are not targeted to be exhaustive or to limit the embodiments to the precise forms disclosed. It will be apparent to one of ordinary skill in the art, after reading this description, that many modifications and variations are possible in view of the above teachings.

Metadata:
Filing Date: 20190430
Publication Date: 20200707
Grant Date: 20200707
Priority Date: 20180530
Inventors: CHEN, TONG
CAI, WENRUI
HEBERLE, ALBERT P.
LI, WEIPING
Assignee: APPLE INC
CPC Classifications: [{"code": "G02B27/0922", "inventive": true, "first": false, "tree": "[]"}, {"code": "G02B27/0922", "inventive": true, "first": true, "tree": "[]"}, {"code": "F21V5/004", "inventive": true, "first": false, "tree": "[]"}, {"code": "F21Y2115/30", "inventive": false, "first": false, "tree": "[]"}, {"code": "F21V5/04", "inventive": true, "first": false, "tree": "[]"}, {"code": "G02B27/0955", "inventive": true, "first": true, "tree": "[]"}, {"code": "F21Y2115/15", "inventive": false, "first": false, "tree": "[]"}, {"code": "G02B27/0955", "inventive": true, "first": false, "tree": "[]"}, {"code": "G02B27/0922", "inventive": true, "first": false, "tree": "[]"}, {"code": "F21Y2115/30", "inventive": false, "first": false, "tree": "[]"}, {"code": "F21V5/004", "inventive": true, "first": false, "tree": "[]"}, {"code": "F21Y2115/15", "inventive": false, "first": false, "tree": "[]"}, {"code": "F21V5/04", "inventive": true, "first": false, "tree": "[]"}, {"code": "G02B27/0955", "inventive": true, "first": true, "tree": "[]"}]
Family ID: 68693660