Patent Publication Number: US-2023135756-A1

Title: Components with wafer level optics

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
     This application is a continuation of U.S. Non-Provisional application Ser. No. 16/675,513 filed Nov. 6, 2019, which claims the benefit of U.S. Provisional Application No. 62/758,458 filed Nov. 9, 2018. U.S. Non-Provisional application Ser. No. 16/675,513 and U.S. Provisional Application No. 62/758,458 are expressly incorporated herein by reference in their entirety. 
    
    
     TECHNICAL FIELD 
     This disclosure relates generally to optics, and in particular to light sources such as a Vertical-Cavity Surface-Emitting Lasers (VCSELs). 
     BACKGROUND INFORMATION 
     There are a variety of application where light sources such as a VCSELs are utilized as light sources. VCSELs are used in fiber optic communication contexts and laser printers, for example. In one particular context, light sources may be utilized to illuminate a subject for purposes of imaging the subject. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Non-limiting and non-exhaustive embodiments of the invention are described with reference to the following figures, wherein like reference numerals refer to like parts throughout the various views unless otherwise specified. 
         FIGS.  1 A- 1 B  illustrate an example head mounted display (HMD) that includes an array of light sources, such as VCSELs, emitting infrared light in an eyebox direction, in accordance with aspects of the disclosure. 
         FIG.  2    illustrates a system that includes a side view of an array of VCSELs illuminating an eyebox area, in accordance with aspects of the disclosure. 
         FIG.  3 A  illustrates an example structure including a plurality of VCSELs, in accordance with aspects of the disclosure. 
         FIG.  3 B  illustrates a lens that includes a transparent substrate with an example 5×5 array of VCSELs, in accordance with aspects of the disclosure. 
         FIGS.  4 A- 4 E  illustrate an example wafer-level fabrication method of a placing wafer level optics (“WLOs”) having different tilt angles and/or different beam divergence angles on VCSELs on the same wafer, in accordance with aspects of the disclosure. 
         FIGS.  5 A- 5 B  illustrate an example wafer-level fabrication method of a placing WLOs having different tilt angles and/or different beam divergence angles on VCSELs on the same wafer, in accordance with aspects of the disclosure. 
         FIG.  6    is a simplified diagram illustrating an example illuminator for eye tracking in an example near-eye display, in accordance with aspects of the disclosure. 
         FIG.  7    is a simplified diagram illustrating an example illuminator for eye tracking in an example near-eye display, in accordance with aspects of the disclosure. 
         FIGS.  8 A- 8 F  illustrate example beam diverging architectures, in accordance with aspects of the disclosure. 
         FIGS.  9 A- 9 B  illustrate example wafers having wafer level optics, in accordance with aspects of the disclosure. 
     
    
    
     DETAILED DESCRIPTION 
     Reference throughout this specification to “one embodiment” or “an embodiment” means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment of the present invention. Thus, the appearances of the phrases “in one embodiment” or “in an embodiment” in various places throughout this specification are not necessarily all referring to the same embodiment. Furthermore, the particular features, structures, or characteristics may be combined in any suitable manner in one or more embodiments. 
       FIG.  1 A  illustrates an example head mounted display (HMD)  100  that includes an array of light sources, such as VCSELs, emitting infrared light in an eyebox direction, in accordance with an embodiment of the disclosure. HMD  100  includes frame  114  coupled to arms  111 A and  111 B. Lenses  121 A and  121 B are mounted to frame  114 . Lenses  121  may be prescription lenses matched to a particular wearer of HMD or non-prescription lenses. The illustrated HMD  100  is configured to be worn on or about a head of a user of the HMD. 
     In  FIG.  1 A , each lens  121  includes a waveguide  160  to direct image light generated by a display  130  to an eyebox area for viewing by a wearer of HMD  100 . Display  130  may include an LCD, an organic light emitting diode (OLED) display, micro-LED display, quantum dot display, pico-projector, or liquid crystal on silicon (LCOS) display for directing image light to a wearer of HMD  100 . 
     The frame  114  and arms  111  of the HMD may include supporting hardware of HMD  100 . HMD  100  may include any of processing logic, wired and/or wireless data interface for sending and receiving data, graphic processors, and one or more memories for storing data and computer-executable instructions. In one embodiment, HMD  100  may be configured to receive wired power. In one embodiment, HMD  100  is configured to be powered by one or more batteries. In one embodiment, HMD  100  may be configured to receive wired data including video data via a wired communication channel. In one embodiment, HMD  100  is configured to receive wireless data including video data via a wireless communication channel. 
     Lenses  121  may appear transparent to a user to facilitate augmented reality or mixed reality where a user can view scene light from the environment around her while also receiving image light directed to her eye(s) by waveguide(s)  160 . Lenses  121  may include an optical combiner  170  for directing reflected infrared light (emitted by light sources  150 ) to an eye-tracking camera (e.g. camera  190 ). Those skilled in the art understand that the array of light sources  150  on a transparent substrate could also be included advantageously in a VR headset where the transparent nature of the optical structure allows a user to view a display in the VR headset. In some embodiments of  FIG.  1 A , image light is only directed into one eye of the wearer of HMD  100 . In an embodiment, both displays  130 A and  130 B are included to direct image light into waveguides  160 A and  160 B, respectively. The term VCSEL is used throughout this disclosure as an example of a light source in general, although those skilled in the art appreciate that in some embodiments, other light sources may be used instead of the specifically described VCSELs. For the purposes of this disclosure, the term “light source” may include a light emitting diode (“LED”), a VCSEL, or a resonant-cavity LED. 
     Lens  121 B includes an array of VCSELs  150  arranged in an example 5×5 array. The VCSELs  150  in the array may not be evenly spaced, in some embodiments. VCSELs  150  may be infrared light sources directing their emitted light in an eyeward direction to an eyebox area of a wearer of HMD  100 . VCSELs  150  may emit near-infrared light having a wavelength of 850 nm or 940 nm, for example. Very small metal traces or transparent conductive layers (e.g. indium tin oxide) may run through lens  121 B to facilitate selective illumination of each VCSEL  150 . Lens  121 A may be configured similarly to the illustrated lens  121 B. 
     While VCSELs  150  may introduce occlusions into an optical system included in an HMD  100 , VCSELs  150  and corresponding routing may be so small as to be unnoticeable or optically insignificant to a wearer of an HMD. Additionally, any occlusion from VCSELs  150  will be placed so close to the eye as to be unfocusable by the human eye and therefore assist in the VCSELs  150  being not noticeable. In addition to a wearer of HMD  100  noticing VCSELs  150 , it may be preferable for an outside observer of HMD  100  to not notice VCSELs  150 . 
       FIG.  1 B  illustrates a footprint of a VCSEL in accordance with embodiments of the disclosure. In some embodiments, each VCSEL  150  has a footprint where the “x” dimension is less than  100  microns and the “y” dimension is less than 100 microns. In some embodiments, each VCSEL  150  has a footprint where the “x” dimension is less than 75 microns and the “y” dimension is less than 75 microns. At these dimensions, the VCSELs  150  may not only be unnoticeable to a wearer of an HMD  100 , the VCSELs  150  may be unnoticeable to an outside observer of HMD  100 . VCSELs having “x” and “y” dimensions between 5 microns and 500 microns may be used. 
       FIG.  2    illustrates a system that  200  that includes a side view of an array of VCSELs  250  illuminating an eyebox area, in accordance with an embodiment of the disclosure. The array of VCSELs  250  includes VCSELs  250 A,  250 B,  250 C,  250 D, and  250 E, in the illustrated embodiment. Of course, VCSELs  250 A,  250 B,  250 C,  250 D, and  250 E, may be part of a larger array of VCSELs such as the twenty-five VCSELs  150  illustrated in  FIG.  1   . VCSEL  250 C illuminates eye  202  with infrared beam  261 . VCSELs  250 A,  250 B,  250 D, and  250 E may also illuminate eye  202  with infrared beams (not illustrated). Infrared light emitted by VCSEL  250 C propagates along optical path  271  and reflects off of eye  202  propagating along optical path  272 . The infrared light propagating along optical path  272  travels through a transparent substrate that houses the VCSELs  250  and encounters combiner  230 . Combiner  230  directs the infrared light to camera  210  along optical path  273 . Combiner  230  may include a polarized volume hologram (PVH), a volume Bragg grating, a hologram, a wavelength selective reflective grating, and/or metalenses, in some embodiments. Combiner  230  may include a Fresnel structure or a distributed array of reflective mirrors that selectively reflect only some portions of the light based on wavelengths or polarization, in some embodiments. 
     Therefore, system  200  shows how VCSELs  250  may illuminate eye  202  with infrared light and shows how camera  210  may capture infrared images of eye  202  by capturing the infrared light. In some embodiments, camera  210  may be configured with a bandpass filter that accepts a narrow-band infrared light that is the same as the narrow-band emitted by VCSELs  250  while the filter rejects other wavelengths. For example, VCSELs  250  may emit narrow-band infrared light centered around 940 nm while camera  210  may include a filter that accepts/transmits infrared light centered around 940 nm while rejecting/blocking other light wavelengths. 
       FIG.  6    is a simplified diagram illustrating an example illuminator  600  for eye tracking in an example near-eye display, according to certain embodiments.  FIG.  6    is merely illustrative and is not drawn to scale. Illuminator  600  may include a substrate  605  positioned in front of (e.g., at a distance of about 10-35 mm from) a user&#39;s eye  640  and within the field of view of user&#39;s eye  640 . Substrate  605  may include one or more types of dielectric materials, such as glass, quartz, sapphire, plastic, polymer, PMMA, crystal, or ceramic, and may be transparent to, for example, both visible light and near-infrared (NIR) light. In some implementations, substrate  605  may be a part of glasses of the near-eye display or a part of display optics described above. Substrate  605  may have a thickness less than about 10 mm, and may have any suitable shape, such as cuboidal, or may have a curved surface. For example, a surface  670  of substrate  605  may be flat or curved. Further, some or all of substrate  605  may be coated with a conductive material that may or may not be transparent to visible light. The conductive material may include any suitable conductor, such as graphene or a transparent conductive oxide such as indium tin oxide (ITO). 
     As shown in  FIG.  6   , a plurality of VCSELs  610  may be mounted on substrate  605 . VCSELs  610  may be attached to substrate  605  in any suitable manner, such as bonding, gluing, or soldering. For example, VCSELs  610  may be die-bonded to substrate  605  using metal-loaded conductive adhesives. Further, VCSELs  610  may be wire-bonded to a conductive coating on surface  670  of substrate  605  via wire  660 . Although  FIG.  6    illustrates a wire bond configuration, implementations of the disclosure may also include flip chip configurations. In addition, electrodes of VCSELs  610  may be electrically connected to a conductive circuit trace  650  within substrate  605 . Conductive circuit trace  650  may be used to control the activity of VCSELs  610 . Although a plurality of VCSELs  610  are shown in  FIG.  6   , other embodiments of the illuminator  600  may have a single VCSEL  610 . Further, the plurality of VCSELs  610  may be arranged in a one-dimensional line or a two-dimensional array. 
     Each VCSEL  610  emits light having an emission cone  620  whose axis is normal to a top surface of the VCSEL  610 , in  FIG.  6   . For example, each VCSEL  610  may be a VCSEL having an emission cone  620  with an angle  680  of up to 50°. VCSELs  610  may be surrounded by or immersed in an encapsulation layer  630  that is an index matched layer, such that a refractive index of encapsulation layer  630  matches a refractive index of substrate  605 . In some embodiments, encapsulation layer  630  is not necessarily index matched to substrate  605 . Encapsulation layer  630  may protect VCSELs  610  from damage. 
     As shown in  FIG.  6   , an axis  615  of each emission cone  620  is normal to the top surface of VCSEL  610  and substrate  605 . As a result, light from some VCSELs  610  may not be angled directly toward eye  640 . This may cause some or all of the light from VCSELs  610  to be wasted by not reaching eye  640 . This may be especially problematic for VCSELs  610  that are positioned near the outer edges of substrate  605 , due to the relatively narrow angle  680  of emission cone  620 . Some embodiments may address this issue by making surface  670  of substrate  605  curved. However, it may be difficult to bond VCSELs  610  on a curved surface. 
       FIG.  7    is a simplified diagram illustrating an example illuminator  700  for eye tracking in an example near-eye display, according to certain embodiments.  FIG.  7    is merely illustrative and is not drawn to scale. The elements shown in  FIG.  7    are similar to those shown in  FIG.  6   , except that each VCSEL  710  is provided with a beam diverting component (not shown in  FIG.  7   ) that directs light from the VCSEL  710  toward eye  740 . The beam diverting components for VCSELs  710  near the outer edges of substrate  705  may be configured to bend the light at a larger tilt angle, in order to direct the light toward eye  740 . Alternatively, some or all of the beam diverting components may bend the light at the same angle, such as an array of light sources that are arranged in a circle whose center is aligned with a center of eye  740 . The beam diverting components are further described below with respect to  FIGS.  8 A- 8 E . 
     The distribution of the light emitted from VCSELs  710  and directed by the beam diverting components toward eye  740  may be controlled by the beam diverting components. For example, each beam diverting component may direct the light from a respective VCSEL  710  in a different direction and may illuminate a different area on eye  740 , depending on the location of VCSEL  710  and the angle at which the beam diverting component bends the light. For example, as discussed above, the beam diverting components for VCSELs  710  (e.g. VCSEL  710 A and  710 D) near the outer edges of substrate  705  may be configured to bend the light at a larger angle so the tilt angle of the emission is larger near the outer edges, while the beam diverting components for VCSELs  710  (e.g. VCSEL  710 B and  710 C) near the middle of substrate  705  (i.e., closest to a normal vector of eye  740 ) may be configured to bend the light at a smaller tilt angle. Further, each area of eye  740  may be illuminated approximately uniformly by VCSELs  710 . Using multiple VCSELs  710  may allow multiple glints to be generated, which may improve eye-tracking accuracy.  FIG.  7    illustrates that the tilt angle of an emission cone  720  may be defined as the angle  793  between an orthogonal axis  790  and a primary emission axis  791  of a given emission cone  720 . Orthogonal axis  790  may be orthogonal to a surface  735  of encapsulation layer  730 , in some examples. The primary emission axis  791  runs through the angle of peak light intensity for the given emission cone  720 , in some examples. In one example, primary emission axis  791  is defined by a light ray running through the geometric center of a given emission cone  720 . In the example of  FIG.  7   , emission cone  720 D has a larger tilt angle  793 D than the tilt angle  793 C of emission cone  720 C because the primary emission axis  791 D has a larger offset from orthogonal axis  790  than primary emission axis  791 C being offset from orthogonal axis  790 . Consequently, emission cone  720 D of VCSEL  710 D is directed to illuminate eye  740  at the appropriate tilt angle  793 D and emission cone  720 C of VCSEL  710 C is directed to illuminate eye  740  at the appropriate tilt angle  793 C. 
       FIGS.  8 A- 8 E  are simplified diagrams illustrating example illuminators for eye tracking having various beam diverting components, according to certain embodiments.  FIGS.  8 A- 8 E  are merely illustrative and are not drawn to scale. As shown in  FIGS.  8 A- 8 E , a VCSEL  810  having an emission area  815  is mounted on a substrate  805 . Beam diverting components  880 ,  885 ,  890 ,  896 ,  897 , and  898  may change the direction of light from emission area  815 . Additionally, the beam diverting components may generate different divergence angles for different VCSELs. VCSEL  810  may be configured such that emission area  815  emits light normal to substrate  805 . However, beam diverting components may change the direction of the light, such that the light is directed toward an eye of the user. For example, beam diverting components  880 ,  885 ,  890 ,  896 ,  897 , and  898  may bend the light such that at least a portion of the light is incident on the eye at an angle with respect to a plane (e.g. plane  203 ) that is normal to a surface of the eye. As discussed above, the angle may be selected such that at least some of the light is reflected by the eye and is incident on the camera by way of optical paths  272  and  273 , for example. Alternatively, beam diverting components  880 ,  885 ,  890 ,  896 ,  897 , and  898  may bend the light such that more of the light is incident on the surface of the eye. 
       FIG.  8 A  illustrates an example illuminator for eye tracking having beam diverting component  880  that is a micro-prism, according to certain embodiments. A shape and a position of the micro-prism may be adjusted to customize the tilt angle at which the light from emission area  815  is bent. The micro-prism may be incorporated into the illuminator and aligned with VCSEL  810  by any suitable method. For example, the micro-prism or an array of micro-prisms may be molded from a substrate, and then the micro-prism may be placed on VCSEL  810  and aligned with emission area  815 . Further, the micro-prism may be patterned into a substrate by grayscale lithography or photolithography or replication or imprinting or molding or diamond turning or some other method. A micro-prism or refractive lens may also be etched into a high index refractive material such as gallium-arsenide (“GaAs”). The gallium-arsenide layer that is etched into a micro-prism or lens may have been grown on top of a VCSEL, or in the case of a flip chip configuration, a lens may be etched into the VCSEL substrate. The micro-prism may also be deposited on VCSEL  810  by pick-and-place deposition. 
       FIG.  8 B  illustrates an example illuminator for eye tracking having beam diverting component  885  that is an off-axis micro-lens, according to certain embodiments. A shape and a position of the micro-lens may be adjusted to customize the tilt angle at which the light from emission area  815  is bent. The micro-lens may be incorporated into the illuminator and aligned with VCSEL  810  by any suitable method. For example, the micro-lens or an array of micro-lenses may be molded from a substrate, and then the micro-lens may be placed on VCSEL  810  such that an optical axis of the micro-lens is offset from an optical axis of emission area  815 . In addition, the micro-lens may be formed by three-dimensional (3D) direct write lithography, injection molding, or inkjet printing or molding or imprinting or casting or replication or 3D printing or diamond turning. A flat metalens may be formed by nanoimprinting or optical lithography. Further, the micro-lens may be deposited on VCSEL  810  by inkjet printing. The micro-lens may also be deposited on VCSEL  810  by pick-and-place deposition. 
       FIG.  8 C  illustrates an example illuminator for eye tracking having beam diverting component  890  that is an inverse micro-prism, according to certain embodiments. A shape and a position of the inverse micro-prism may be adjusted to customize the tilt angle at which the light from emission area  815  is bent. The inverse micro-prism may be incorporated into the illuminator and aligned with VCSEL  810  by any suitable method. For example, the inverse micro-prism may be patterned into a substrate by grayscale lithography or photolithography, and may then be placed on VCSEL  810  and aligned with emission area  815 . Further, the inverse micro-prism may be formed by injection molding. In addition, the inverse micro-prism may be formed by diamond turning in an encapsulation layer that surrounds VCSEL  810 . The inverse micro-prism may also be deposited on VCSEL  810  by pick-and-place deposition. For the illuminators shown in  FIGS.  8 A,  8 B, and  8 C , the VCSELs  810  and beam diverting components  880 ,  885 , and  890  may be immersed in an encapsulant (not shown), where the encapsulant may have a different refractive index than the beam diverting components  880 ,  885 , and  890 . 
       FIGS.  8 D and  8 E  illustrate example illuminators for eye tracking having beam diverting components  896  and  897 , respectively, that are gratings, according to certain embodiments. A period, slant angle, material(s), shape, and/or position of the grating may be adjusted to customize the tilt angle at which the light from emission area  815  is bent. For example, a shorter grating period diffracts light at a larger tilt angle and may be used on the outer edges of the grating. Slanted gratings increase the amount of light diffracted in the −1 or +1 diffraction order. The grating may be incorporated into the illuminator and aligned with VCSEL  810  by any suitable method. For example, the grating may be formed in a substrate by etching and nanoimprinting, or by holography or replication. Further, as shown in  FIG.  8 D , the grating may be a surface relief grating (SRG)  896  that is formed by direct imprinting on a surface of VCSEL  810 . In addition, the grating may be fabricated as a roll that forms an encapsulation layer on VCSEL  810 . The grating may also be a thin phase hologram of a thick volume Bragg grating  897 , as shown in  FIG.  8 E . 
       FIG.  8 F  illustrates an example illuminator for eye tracking having beam diverting component  898  that is an inclined plane, according to certain embodiments. A shape and a position of the inclined plane may be adjusted to customize the tilt angle at which the light from emission area  815  is bent. The inclined plane may be incorporated into the illuminator and aligned with VCSEL  810  by any suitable method. For example, grayscale lithography may be used to pattern small bumps on a bottom surface of VCSEL  810 , such that a coefficient of friction is sufficient to prevent VCSEL  810  from sliding off of the inclined plane. Alternatively, VCSEL  810  may be mounted with solder bumps, where the bonding pads have different thicknesses, different amounts of solder are used, and/or VCSEL  810  is held at a predetermined angle that is not parallel with the bonded surface  807  of substrate  805 . 
       FIG.  3 A  illustrates an example structure  300  including a plurality of VCSELs  350 . The plurality of VCSELs  350  are configured to emit narrow-band infrared light through their emission apertures. VCSEL optics  370  are formed over the emission apertures of the plurality of VCSELs and the VCSEL optics  370  may provide different divergence angles to the narrow-band infrared light emitted by the VCSELs  350 . VCSEL optics  370  may also provide different tilt angles for the emitted infrared light. In one embodiment, the tilt angle of a given VCSEL is defined as the average emission angle of the emitted infrared beam relative to a vector normal to the substrate at the given VCSEL. In one embodiment, the tilt angle of a given VCSEL is defined as the average emission angle of the emitted infrared beam relative to a vector normal to the substrate of a designated VCSEL. For example, the tilt angle of beam  359 C may be approximately zero where vector  357 C (vector  357 C being normal to the substrate  310  at VCSEL  350 C) illustrates the average emission angle of beam  359 C is approximately zero. The tilt angle of beam  359 E illustrated by vector  357 E may be 20 degrees tilted with respect to vector  357 C. Or the tilt angle of beam  359 E illustrated by vector  357 E may be 20 degrees tilted with respect to a vector (not illustrated) that is normal to substrate  310  at the position of VCSEL  350 E. These tilt angles may be different when substrate  310  is not planar, for example. 
     Structure  300  shows that VCSELs  350  are disposed on substrate  310 . In some embodiments, substrate  310  is an optically transparent substrate such as glass or plastic and incorporated into lens  121 , for example. Structure  300  illustrates an enclosing layer  388  that may be disposed between VCSELs  350 . 
     The VCSEL optics  370  may include the characteristics of the embodiments of beam diverting components  880 ,  885 ,  890 ,  896 ,  897 , and  898 , for example. VCSEL optics  370  may decrease their divergence angles as the VCSELs optics  370  get closer to a boundary of the substrate. For example, the divergence angle associated with beam  359 A may be smaller than the divergence angle associated with beam  359 B, which may be smaller than the divergence angle associated with beam  359 C. And, the divergence angle associated with beam  359 E may be smaller than the divergence angle associated with beam  359 D, which may be smaller than the divergence angle associated with beam  359 C. The divergence angle of beam  359 C may be 60 degrees in some embodiments. In one embodiment, the VCSEL optics  370  may increase their divergence angles as the VCSEL optics  370  get closer to a boundary of the substrate. 
     VCSEL optics  370  may increase a tilt angle of the VCSEL optic as the VCSEL optics get closer to a boundary of the substrate. For example, the tilt angle associated with vector  357 A of beam  359 A may be larger than the tilt angle associated with vector  357 B of beam  359 B, which may be larger than the tilt angle associated with a vector  357 C of beam  359 C. And, the tilt angle associated with a vector  357 E of beam  359 E may be larger than the tilt angle associated with vector  357 D of beam  359 D, which may be larger than the tilt angle associated with vector  357 C of beam  359 C. The tilt angle of beam  359 C may be approximately zero degrees. 
       FIG.  3 B  illustrates a lens  321  that includes a transparent substrate  310  with an example 5×5 array of VCSELs having VCSEL optics  370 A-Y. VCSEL optics  370 J-Y may be configured to provide larger tilt angles to the VCSELs they are disposed on since they may be farther from a center of an eye. VCSEL optics  370 B-I may be configured to provide tilt angles to the VCSELs they are disposed on that are less than the tilt angles of VCSEL optics  370 J-Y. VCSEL optic  370 A may be configured to provide a tilt angle to the VCSEL it is disposed over of zero degrees or a tilt angle that is less than the tilt angles provided by VCSEL optics  370 B-I. 
     Fabricating VCSELs with different VCSEL optics that provide different tilt angles and/or different divergence angles (to provide different beam shapes) may be created by fabricating a VCSEL wafer that includes a plurality of VCSELs that have different VCSEL optics  370  in different zones of the VCSEL wafer.  FIG.  9 A  illustrates a VCSEL wafer  900  having first Wafer Level Optics (WLO) on a first zone  921  of VCSEL mesas, second WLOs on a second zone  922  of VCSEL mesas, and third WLOs on a third zone  923  of VCSEL mesas.  FIG.  9 B  illustrates another example VCSEL wafer  950  having first Wafer Level Optics (WLO) on a first zone  971  of VCSEL mesas, second WLOs on a second zone  972  of VCSEL mesas, third WLOs on a third zone  973  of VCSEL mesas, and fourth WLOs on a fourth zone  974  of VCSEL mesas. The WLO on the different zones may be configured to provide different tilt angles and different beam shaping (e.g. divergence angles). A pick-and-place machine may then select, VCSELs with their corresponding WLO attached to the VCSEL that have different tilt angle and divergence angles where the VCSELs were grown on the same wafer. Although  FIG.  9 A  illustrate three zones  921 ,  922 , and  923  and  FIG.  9 B  illustrates four zones  971 ,  972 ,  973 ,  974 , it is appreciated by those skilled in the art that any number of zones of a VCSEL corresponding to different VCSEL optics may be utilized. In one embodiment, a VCSEL wafer may have 16 zones or 24 zones, for example. 
     Once a VCSEL is grown on a semiconductor substrate (e.g. GaAs) a replication or casting technique may be utilized to cast Wafer Level Optics that include refractive optics, surface relief gratings, catadioptric lenses, reflective lenses, and/or engineered diffusers, as VCSEL optics  370 , for example. Fabricating the VCSELs  350  with VCSEL optics  370  may also include lithography (grayscale or binary) that includes applying a coating/layer on top of VCSELs  350 . Fabricating VCSELs with VCSEL optics  370  may also include a modification of the illuminator window using lithography (grayscale or binary). Furthermore, in some implementations of the disclosure, a micro-prism or refractive lens may also be etched into gallium-arsenide or another high index material. The gallium-arsenide layer or other high index material that is etched into a micro-prism or lens may be grown on top of a VCSEL, or in the case of a flip chip configuration, a lens may be etched into the VCSEL substrate. 
       FIGS.  4 A- 4 E  illustrate an example wafer-level fabrication method of a placing WLOs having different tilt angles and/or different beam divergence angles on VCSELs on the same wafer. In  FIG.  4 A , a structure  400  is provided that includes VCSEL mesas  453 A-E disposed on a semiconductor substrate  411 . The semiconductor substrate may be GaAs, in some embodiments.  FIG.  4 B  illustrates forming an optical encapsulant layer  413  onto a plurality of VCSEL mesas  453 .  FIGS.  4 C and  4 D  illustrate pressing a stamp  444  into the encapsulant layer  413 . The stamp  444  includes negatives  447  of the wafer level optics (WLO) aligned with the VCSEL mesas. The negatives  447  may be different and be aligned with VCSELs in different zones. For example, negatives  447 A and  447 E may be aligned with VCSELs in a first zone, negatives  447 B and  447 D may be aligned with VCSELs in a second zone, and negative  447 C aligned with VCSEL(s) in a third zone. The different negatives may have different characteristics that form the VCSEL optics having different divergence angles and tilt angles, as described in  FIG.  3 A . After (or during) a curing of layer  413 , the stamp may be removed to leave VCSEL optics  434 , as in  FIG.  4 E . When the wafer is diced, structure  450  provides a VCSEL having a WLO that has the characteristics of optical structure  434 B. 
       FIGS.  5 A- 5 B  illustrate an example wafer-level fabrication method of a placing WLOs having different tilt angles and/or different beam divergence angles on VCSELs on the same wafer.  FIG.  5 A  illustrates wafer level optic layer  544  being aligned with the VCSEL mesas  453  and  FIG.  5 B  illustrates the VCSEL optics  534  being disposed over their respective VCSEL mesa  453 . Wafer Level Optic Layer  544  may be a rigid material and be bonded to the VCSELs  350  with an optical grade adhesive. When the wafer is diced, structure  550  provides a VCSEL having a WLO that has the characteristics of optical structure  534 B. 
     Embodiments of the invention may include or be implemented in conjunction with an artificial reality system. Artificial reality is a form of reality that has been adjusted in some manner before presentation to a user, which may include, e.g., a virtual reality (VR), an augmented reality (AR), a mixed reality (MR), a hybrid reality, or some combination and/or derivatives thereof. Artificial reality content may include completely generated content or generated content combined with captured (e.g., real-world) content. The artificial reality content may include video, audio, haptic feedback, or some combination thereof, and any of which may be presented in a single channel or in multiple channels (such as stereo video that produces a three-dimensional effect to the viewer). Additionally, in some embodiments, artificial reality may also be associated with applications, products, accessories, services, or some combination thereof, that are used to, e.g., create content in an artificial reality and/or are otherwise used in (e.g., perform activities in) an artificial reality. The artificial reality system that provides the artificial reality content may be implemented on various platforms, including a head-mounted display (HMD) connected to a host computer system, a standalone HMD, a mobile device or computing system, or any other hardware platform capable of providing artificial reality content to one or more viewers. 
     The term “processing logic” in this disclosure may include one or more processors, microprocessors, multi-core processors, Application-specific integrated circuits (ASIC), and/or Field Programmable Gate Arrays (FPGAs) to execute operations disclosed herein. In some embodiments, memories (not illustrated) are integrated into the processing logic to store instructions to execute operations and/or store data. Processing logic may also include analog or digital circuitry to perform the operations in accordance with embodiments of the disclosure. 
     A “memory” or “memories described in this disclosure may include one or more volatile or non-volatile memory architectures. The “memory” or “memories” may be removable and non-removable media implemented in any method or technology for storage of information such as computer-readable instructions, data structures, program modules, or other data. Example memory technologies may include RAM, ROM, EEPROM, flash memory, CD-ROM, digital versatile disks (DVD), high-definition multimedia/data storage disks, or other optical storage, magnetic cassettes, magnetic tape, magnetic disk storage or other magnetic storage devices, or any other non-transmission medium that can be used to store information for access by a computing device. 
     The above description of illustrated embodiments of the invention, including what is described in the Abstract, is not intended to be exhaustive or to limit the invention to the precise forms disclosed. While specific embodiments of, and examples for, the invention are described herein for illustrative purposes, various modifications are possible within the scope of the invention, as those skilled in the relevant art will recognize. 
     These modifications can be made to the invention in light of the above detailed description. The terms used in the following claims should not be construed to limit the invention to the specific embodiments disclosed in the specification. Rather, the scope of the invention is to be determined entirely by the following claims, which are to be construed in accordance with established doctrines of claim interpretation.