See-through metrology system, apparatus, and method for optical devices - Patents.com

Abstract

[0001] Embodiments of the present disclosure relate to optical devices for augmented, virtual, and / or mixed reality applications. In one or more embodiments, an optical device metrology system is configured to measure multiple see-through metrics of the optical device.

Description

[Technical field]

[0001] SUMMARY OF THE DISCLOSURE

[0002] Embodiments of the present disclosure relate to optical devices for augmented, virtual, and / or mixed reality applications. In one or more embodiments, an optical device metrology system is configured to measure a number of see-through metrics of the optical device. [Background technology]

[0002] Virtual reality is generally considered to be a computer-generated, simulated environment in which the user has a clear perception of physical presence. Virtual reality experiences are generated in 3D and viewed through a head-mounted display (HMD) (e.g., glasses or other wearable display device with near-eye display panels as lenses for displaying a virtual reality environment that replaces the real environment).

[0003] Augmented reality, however, enables an experience in which a user can look through the display lenses of glasses or other HMD devices to see the surrounding environment, but also see images of virtual objects that are generated for display and appear as part of this environment. Augmented reality may include any type of input (e.g., voice input and haptic input), as well as virtual images, graphics, and video that enhance or extend the environment the user experiences. As an emerging technology, augmented reality has many challenges and design constraints.

[0004] One such challenge is to display a virtual image superimposed on the surrounding environment. An extended waveguide coupler is used to assist in the image superimposition. Generated light is incoupled to the extended waveguide coupler, propagates through the extended waveguide coupler, and outcoupled from the extended waveguide coupler and superimposed on the surrounding environment. Light is incoupled to and outcoupled from the extended waveguide coupler using a surface relief grating. The intensity of the outcoupled light may not be well controlled.

[0005] Thus, there is a need in the art for optical device metrology systems and methods. Summary of the Invention

[0006] SUMMARY OF THE DISCLOSURE

[0002] Embodiments of the present disclosure relate to optical devices for augmented, virtual, and / or mixed reality applications. In one or more embodiments, an optical device metrology system is configured to measure a number of see-through metrics of the optical device.

[0007] In one embodiment, the optical device metrology system includes a stage configured to move a tray along a stage path, a first light engine mounted above the stage path and configured to direct an upper light beam toward the stage path, and a second light engine mounted below the stage path and configured to direct a lower light beam toward the stage path. The optical device metrology system includes a detector mounted above the stage path and configured to receive a projected light beam projected from the stage path, and a controller in communication with the stage, the first light engine, the second light engine, and the detector. The controller includes instructions that, when executed, cause the stage to position the optical device above the second light engine to align the optical device with the second light engine, and cause the second light engine to direct a first light beam from the second light engine toward the optical device. The instructions also cause the detector to capture a plurality of first images of the first light beam projected from the optical device as the first projected light beam, and cause the stage to position the optical device away from the second light engine to offset the position of the optical device from the second light engine. The instructions also cause the second light engine to direct a second light beam from the second light engine towards a detector, cause the detector to capture a plurality of second images of the second light beam, and compare the plurality of second images to the plurality of first images to determine a see-through transmittance metric of the optical device.

[0008] In one embodiment, the optical device metrology system includes a stage configured to move a tray along a stage path, a first light engine mounted above the stage path and configured to direct an upper light beam toward the stage path, a second light engine mounted below the stage path and configured to direct a lower light beam toward the stage path, and a detector mounted above the stage path and configured to receive a projected light beam projected from the stage path, the detector being aligned with the second light engine and offset from the first light engine.

[0009] In one embodiment, a method of analyzing an optical device includes positioning the optical device over the light engine to align the optical device with the light engine and directing a first light beam from the light engine toward the optical device. The method includes capturing a plurality of first images of the first light beam projected from the optical device as a first projected light beam using a detector and positioning the optical device away from the light engine to offset the optical device from the light engine. The method includes directing a second light beam from the light engine toward the detector and capturing a plurality of second images of the second light beam and comparing the plurality of second images to the plurality of first images to determine a see-through transmittance metric of the optical device.

[0010] So that the above-mentioned features of the present disclosure can be understood in detail, a more particular description of the present disclosure, briefly summarized above, will be obtained by reference to embodiments, some of which are illustrated in the accompanying drawings, which are to be noted, however, that the accompanying drawings depict only exemplary embodiments and therefore should not be considered as limiting its scope, which may admit of other equally effective embodiments. [Brief description of the drawings]

[0011] [Figure 1A] FIG. 2 is a perspective front view of a substrate according to one embodiment. [Figure 1B] FIG. 1 is a perspective front view of an optical device according to one embodiment. [Diagram 2] FIG. 1 is a schematic diagram of an optical device metrology system, according to one embodiment. [Figure 3A] 3 is a schematic partial cross-sectional view of the first subsystem shown in FIG. 2 according to one embodiment. [Figure 3B] 3 is a schematic partial cross-sectional view of the second subsystem shown in FIG. 2 according to one embodiment. [Figure 3C] 3 is a schematic partial cross-sectional view of the third subsystem shown in FIG. 2 according to one embodiment. [Figure 4A]FIG. 3B is a schematic diagram of the configuration of the first subsystem shown in FIGS. 2 and 3A according to one embodiment. [Figure 4B] FIG. 3B is a schematic diagram of the configuration of the first subsystem shown in FIGS. 2 and 3A according to one embodiment. [Figure 4C] FIG. 3B is a schematic diagram of the configuration of the first subsystem shown in FIGS. 2 and 3A according to one embodiment. [Figure 4D] FIG. 3B is a schematic diagram of the configuration of the first subsystem shown in FIGS. 2 and 3A according to one embodiment. [Figure 4E] FIG. 3C is a schematic diagram of the second subsystem configuration shown in FIGS. 2 and 3B according to one embodiment. [Figure 4F] FIG. 4 is a schematic diagram of a configuration of the third subsystem shown in FIGS. 2 and 3C according to one embodiment. [Figure 4G] FIG. 4 is a schematic diagram of a configuration of the third subsystem shown in FIGS. 2 and 3C according to one embodiment. [Diagram 5] FIG. 2 is a schematic diagram of an image according to one embodiment. [Figure 6] 1A-C are schematic diagrams of images according to one embodiment. [Figure 7] 1A-C are schematic diagrams of images according to one embodiment. [Figure 8] FIG. 2 is a schematic diagram of an image according to one embodiment. [Figure 9] 1A-C are schematic diagrams of images according to one embodiment. [Figure 10] 1 is a schematic block diagram of a method for analyzing an optical device, according to one embodiment. [Figure 11] 1 is a schematic block diagram of a method for analyzing an optical device, according to one embodiment. [Figure 12] 1 is a schematic block diagram of a method for analyzing an optical device, according to one embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0012] For ease of understanding, the same reference numerals have been used, where possible, to designate identical elements that are common to several figures. It is envisioned that elements and features of one embodiment may be beneficially incorporated in other embodiments without further recitation.

[0013] SUMMARY OF THE DISCLOSURE

[0002] Embodiments of the present disclosure relate to optical devices for augmented, virtual, and / or mixed reality applications. In one or more embodiments, an optical device metrology system is configured to measure a number of see-through metrics of the optical device.

[0014] 1A is a perspective front view of a substrate 101 according to one embodiment. The substrate includes a plurality of optical devices 100 disposed on a surface 103 of the substrate 101. The optical devices 100 are waveguide combiners utilized for virtual reality, augmented reality, and / or mixed reality. The optical devices 100 may be part of the substrate 101 such that the optical devices 100 may be cut to be separated from the substrate 101.

[0015] 1B is a perspective front view of optical device 100, according to one embodiment. It should be understood that optical device 100 described herein is an exemplary optical device, and that other optical devices (such as optical devices other than waveguide couplers) may be used with or modified to achieve aspects of the present disclosure.

[0016] The optical device 100 includes a plurality of optical device structures 102 disposed on a surface 103 of a substrate 101. The optical device structures 102 can be nanostructures having submicron dimensions (e.g., nano-sized dimensions). Areas of the optical device structures 102 correspond to one or more gratings 104, such as a first grating 104a, a second grating 104b, and a third grating 104c. In one embodiment that can be combined with other embodiments, the optical device 100 includes at least a first grating 104a corresponding to an input coupling grating and a third grating 104c corresponding to an output coupling grating. In one embodiment that can be combined with other embodiments described herein, the optical device 100 also includes a second grating 104b corresponding to an intermediate grating. The optical device structures 102 can be angled or binary. The optical device structures 102 are rectangular. The optical device structure 102 may have other shapes, including, but not limited to, circular, triangular, elliptical, regular polygonal, irregular polygonal, and / or irregularly shaped cross-sections.

[0017] In operation (such as in the case of augmented reality glasses), the input coupling grating 104a receives an incident beam of light (virtual image) having an intensity from a microdisplay. The incident beam is split by the optical device structure 102 into a T1 beam having all of the intensity of the incident beam in order to direct the virtual image to the intermediate grating 104b (if utilized) or the output coupling grating 104c. In one embodiment, which can be combined with other embodiments, the T1 beam undergoes total internal reflection (TIR) ​​through the optical device 100 until the T1 beam comes into contact with the optical device structure 102 of the intermediate grating 104b. The optical device structure 102 of the intermediate grating 104b diffracts the T1 beam into a T-1 beam, which undergoes TIR through the optical device 100 to the optical device structure 102 of the output coupling grating 104c. The optical device structure 102 of the output coupling grating 104c outcouples the T-1 beam to the user's eye to modulate the field of view of the virtual image generated from the microdisplay from the user's viewpoint, further increasing the viewing angle at which the user can see the virtual image. In one embodiment, which can be combined with other embodiments, the T1 beam undergoes total internal reflection (TIR) ​​through the optical device 100 until the T1 beam contacts the optical device structure 102 of the output coupling grating and is outcoupled to modulate the field of view of the virtual image generated from the microdisplay.

[0018] To facilitate ensuring that optical device 100 meets image quality standards, metrology metrics of the manufactured optical device 100 are obtained prior to use of optical device 100.

[0019] 2 is a schematic diagram of an optical device metrology system 200 according to one embodiment. The optical device metrology system 200 embodiments described herein provide the ability to obtain multiple metrology metrics with increased throughput. The metrology metrics include an angular uniformity metric, a contrast metric, an efficiency metric, a color uniformity metric, a modulation transfer function (MTF) metric, a field of view (FOV) metric, a ghost image metric, an eyebox metric, a view leakage metric, a see-through distortion metric, a see-through flare metric, a see-through ghost image metric, and a see-through transmittance metric. Throughput is increased through the use of a feed system connected to each of one or more subsystems of the optical device metrology system 200.

[0020] The optical device metrology system 200 includes a first subsystem 202, a second subsystem 204, and a third subsystem 206. Each of the first subsystem 202, the second subsystem 204, and the third subsystem 206 includes a respective body 201A-201C having a first opening 203 and a second opening 205, and a stage 207 is movable through the first opening 203 and the second opening 205 along a stage path 211 parallel to and / or within the XY plane. The stage 207 is operable to move in the X, Y, and Z directions in the bodies 201A-201C of the first subsystem 202, the second subsystem 204, and the third subsystem 206. The stage 207 includes a tray 209 operable to hold the optical device 100 (as shown herein) or one or more substrates 101. The stage 207 and tray 209 may be transparent such that metrology metrics obtained by the first subsystem 202, the second subsystem 204, and the third subsystem 206 are not affected by the translucency of the stage 207 of the tray 209. The first subsystem 202, the second subsystem 204, and the third subsystem 206 are in communication with a controller 208 operable to control the operation of the first subsystem 202, the second subsystem 204, and the third subsystem 206. The controller 208 includes instructions stored in a non-transitory computer readable medium (such as a memory). The instructions, when executed by a processor of the controller 208, cause operations described herein to be performed. The instructions, when executed by a processor of the controller 208, cause one or more operations of one or more of methods 1000, 1100, and / or 1200 to be performed.

[0021] The instructions of the controller 208 include machine learning and / or artificial intelligence algorithms to optimize operations. In one embodiment, which can be combined with other embodiments, the instructions of the controller 208 include a machine learning (ML) model that is a regression model and averages data (such as image data collected using metrics determined herein and / or alignment module 494). In one example, which can be combined with other examples, the ML model is used to average and merge the data to determine optimized pitch and tilt of the projection structure, lenses, and cameras. In one example, which can be combined with other examples, the ML model is used to average and merge the data to determine optimized power to apply to the light source and laser source to generate the light beam and laser beam.

[0022] The first subsystem 202 is operable to obtain one or more metric metrics including an angular uniformity metric, a contrast metric, an efficiency metric, a color uniformity metric, an MTF metric, an FOV metric, a ghost image metric, or an eyebox metric. The second subsystem 204 is operable to obtain a view leakage metric. The third subsystem 206 is operable to obtain one or more see-through metrology metrics including a see-through distortion metric, a see-through flare metric, a see-through ghost image metric, or a see-through transmittance metric.

[0023] The optical device metrology system 200 is configured to determine a view leak metric, one or more see-through metrics, and one or more other measurement metrics for multiple optical devices (such as waveguide couplers) on a single system using a single stage path 211.

[0024] Figure 3A is a schematic partial cross-sectional view of the first subsystem 202 shown in Figure 2 according to one embodiment. The first subsystem 202 may include one or more of the configurations 400A, 400B, 400C, 400D shown in Figures 4A-4D.

[0025] As shown in FIG. 3A, the first subsystem 202 includes an upper portion 304 oriented toward the top side of the optical device 100 and a lower portion 306 oriented toward the bottom side of the optical device 100.

[0026] The first subsystem 202 includes a first body 201A having a first opening 203 and a second opening 205, through which a stage 207 is movable. The stage 207 is configured to move a tray 209 along a stage path 211. The first subsystem 202 includes a first light engine 310 positioned within the first body 201A and mounted above the stage path 211. The first light engine 310 is an upper light engine. The first light engine 310 is configured to direct a first light beam toward the stage path 211. In one embodiment, which can be combined with other embodiments, the first light beam is directed with a light pattern design toward the stage path 211 and toward one of the optical devices 100 for determining a metrology metric. The first subsystem 202 includes a first detector 312 positioned within the first body 201A and mounted above the stage path 211 to receive a first projected light beam projected upward from the stage path 211. The present disclosure contemplates that the projected light may be light reflected from the optical device or light transmitted through the optical device. The first detector 312 is a reflective detector. The first subsystem 202 includes a second detector 316 positioned within the first body 201A and mounted below the stage path 211 to receive a second projected light beam projected downward from the stage path 211. The second detector 316 is a transmissive detector. The first projected light beam and the second projected light beam are projected from the optical device 100. In one embodiment, which can be combined with other embodiments, the first light engine 310 is configured to direct a first light beam towards an input coupling grating of the optical device 100, and the first and second detectors 312, 316 are configured to receive projected light beams projected from the output coupling grating of the optical device 100.

[0027] The upper portion 304 of the first subsystem 202 includes an alignment detector 308. The alignment detector 308 includes a camera. The alignment detector 308 is operable to determine the position of the stage 207 and the optical device 100. The lower portion 306 of the first subsystem 202 includes a code reader 314 mounted below the stage path 211. The code reader 314 is operable to read a code on the optical device 100, such as a Quick Response (QR) code or a barcode on the optical device 100. The code read by the code reader 314 may include instructions for obtaining one or more metrology metrics of various optical device 100.

[0028] Figure 3B is a schematic partial cross-sectional view of the second subsystem 204 shown in Figure 2, according to one embodiment. The second subsystem 204 can include at least one configuration 400E, as shown in Figure 4E.

[0029] As shown in FIG. 3B, the second subsystem 204 includes an upper portion 304 oriented toward the top side of the optical device 100 and a lower portion oriented toward the bottom side of the optical device 100.

[0030] The second subsystem 204 includes a second body 201B and a second light engine 360 ​​positioned within the second body 201B and mounted above the stage path 211. The second light engine 360 ​​is configured to direct a second light beam towards the stage path 211. The top 304 of the first subsystem 202 includes an alignment detector 308.

[0031] The second subsystem 204 includes a face illumination detector 318 configured to receive a third projected light beam projected upward from the stage path 211. The third projected light beam is projected from the optical arrangement 100. The lower portion 306 of the second subsystem 204 includes a code reader 314.

[0032] The face illumination detector 318 is operable to capture images to obtain a display leakage metric of the optical device 100. In one embodiment, which can be combined with other embodiments, a light pattern design is directed from the second light engine 360 ​​towards the optical device 100 and images of the light outside the user's eye positions are obtained and processed to obtain an eyebox metric.

[0033] Figure 3C is a schematic partial cross-sectional view of the third subsystem 206 shown in Figure 2, according to one embodiment. The third subsystem 206 can include one or more configurations 400F and / or 400G, as shown in Figures 4F and 4G.

[0034] As shown in FIG. 3C, the third subsystem 206 includes an upper portion 304 oriented toward the top side of the optical device 100 and a lower portion 306 oriented toward the bottom side of the optical device 100. The third subsystem 206 includes a first light engine 370 mounted above the stage path 211 and configured to direct an upper light beam toward the stage path 211, a second light engine 380 mounted below the stage path 211 and configured to direct a lower light beam toward the stage path 211, and a detector 390 mounted above the stage path and configured to receive a projected light beam projected from the stage path 211. The upper portion 304 of the third subsystem 206 includes an alignment detector 308. The detector 390 is a reflection detector. The detector 390 detects a light beam projected (e.g., reflected) from the output coupling grating from the upper side of the optical device 100. The lower portion 306 of the third subsystem 206 includes a code reader 314. First light engine 370, second light engine 380, and detector 390 are each positioned within third body 201C of third subsystem 206.

[0035] 4A is a schematic diagram of a configuration 400A of the first subsystem 202 shown in FIGURES 2 and 3A according to one embodiment. Configuration 400A includes a first light engine 310, a first detector 312, and a second detector 316.

[0036] The first light engine 310 includes a first illuminator 401, which includes a first light source 402 and a first projection structure 404. The first light engine 310 includes a first lens 406 positioned between the first illuminator 401 and the stage path 211. The first light engine 310 includes one or more devices 413 (one shown in FIG. 4A) positioned between the first lens 406 and the stage path 211. The one or more devices 413 include one or more of a quarter wave plate or a linear polarizer. In one embodiment that may be combined with other embodiments described herein, the first light engine 310 is configured to emit (e.g., project) light beams in the red, green, and blue spectrums. In one example that may be combined with other examples, the first light engine 310 is configured to modulate or pulse light beams between the red, green, and blue spectrums. In one example, which can be combined with other examples, the first light engine 310 includes three light sources, each configured to emit light in the red spectrum, light in the green spectrum, and light in the blue spectrum, respectively.

[0037] The first projection structure 404 includes one or more of a display and / or a reticle. In one embodiment that can be combined with other embodiments, the first projection structure 404 includes one or more of a microdisplay, a spatial light modulator (SLM), and / or a reticle. In one example that can be combined with other examples, the SLM includes one or more of a digital micromirror device (DMD) and / or a liquid crystal on silicon (LCOS) emitter.

[0038] The first detector 312 includes a first camera 412 and a second lens 410 positioned between the first camera 412 and the stage path 211. The second detector 316 includes a second camera 416 and a third lens 414 positioned between the second camera 416 and the stage path 211. In the embodiment shown in Figure 4A, the first projection structure 404 and the first lens 406 are oriented parallel to the stage path 211.

[0039] The optical device 100 is positioned such that the input coupler 121 of the optical device 100 is aligned with the first light engine 310, and the output coupler 122 of the optical device 100 is aligned with the first detector 312 and the second detector 316. A first light beam B1 is directed from the first light engine 310 towards the input coupler 121 of the optical device 100. The first detector 312 captures a plurality of first images of the first projected light beam BP1 projected from the output coupler 122 in the red, green, and blue spectra. The second detector 316 captures a plurality of second images of the second projected light beam BP2 projected from the output coupler 122 in the red, green, and blue spectra.

[0040] The first image and the second image are full-field images. One or more of the first image and / or the second image are processed (such as using the controller 208) to determine a plurality of first metrics of the optical apparatus 100.

[0041] The plurality of first metrics includes an angular uniformity metric. The angular uniformity metric may represent a ratio of light intensity over a portion of the light field. For angular uniformity, processing one or more image metrics of the plurality of first images or the plurality of second images includes comparing one or more first portions of the light pattern design to one or more second portions of the light pattern design within a single image. For the angular uniformity metric, the first light ray B1 incoupled to the input coupler 121 undergoes TIR until it is outcoupled (e.g., projected (e.g., reflected)) to the first detector 312.

[0042] The plurality of first metrics includes a contrast metric. The contrast metric may represent a contrast between the brightest captured light in the image and the darkest captured light in the image. For the contrast metric, processing one or more of the plurality of first images or the plurality of second images includes comparing one or more bright portions of the light pattern design to one or more dark portions of the light pattern design in a single image. For the contrast metric, the first light beam B1 incoupled to the input coupler 121 undergoes TIR until the incoupled first light beam B1 is outcoupled (e.g., projected (e.g., reflected)) to the first detector 312.

[0043] The plurality of first metrics includes a color uniformity metric. The color uniformity metric may represent one or more ratios between red light, green light, and blue light in a field. One or more of the plurality of first images, the plurality of second images, and / or the plurality of third images (described below in connection with FIG. 4E) capture a red spectrum, a green spectrum, and a blue spectrum. For a color uniformity metric, processing one or more of the plurality of first images or the plurality of second images includes comparing a red spectrum image with a green spectrum image and a blue spectrum image using the same field area. For a color uniformity metric, the first light beam B1 incoupled to the input coupler 121 undergoes TIR until it is outcoupled (e.g., projected (e.g., reflected)) to the first detector 312.

[0044] The first metric includes an efficiency metric. For the efficiency metric, prior to the capture of the first images and the capture of the second images, the second detector 316 is positioned to align with the input coupler 121 of the optical device 100 in a calibration position (shown by dashed lines for the second detector 316 in FIG. 4A). While the second detector 316 is in the calibration position, the first light engine 310 directs a calibration beam toward the input coupler 121 of the optical device 100, and the second detector 316 captures one or more calibration images of the calibration projection beam CP1 projected from the input coupler 121 of the optical device 100. The one or more calibration images are full-field images. The second detector 316 is then positioned to align with the output coupler 122 of the optical device 100. For the efficiency metric, a first light ray B1 incoupled to the input coupler 121 undergoes TIR until it is outcoupled (e.g., projected (e.g., reflected, etc.)) to a first detector 312 and outcoupled (e.g., projected (e.g., transmitted, etc.)) to a second detector 316. The first image is a reflected image and the second image is a transmitted image.

[0045] For an efficiency metric, processing one or more of the plurality of first images or the plurality of second images includes comparing one or more calibration images to the plurality of first images and the plurality of second images.

[0046] The one or more first metrics include a modulation transfer function (MTF) metric. For the MTF metric, prior to capturing the first images and capturing the second images, a calibration beam is directed from the first light engine 301 towards the second detector 316. While the second detector 316 is displaced from the optical device 100, the second detector 316 captures one or more calibration images of the calibration beam. The second detector 316 may be in a calibration position, shown in ghost in FIG. 4A, and aligned with the first light engine 310, while the optical device 100 may be positioned away from the second detector 316 (as shown in ghost for the optical device 100 in FIG. 4A) so as to be out of the field of view of the second detector 316 and the first light engine 310. The second detector 316 may then be positioned to be aligned with the first detector 312. In one embodiment, which can be combined with other embodiments, the second image is captured before capturing the first image. For the MTF metric, the first light ray B1 incoupled to the input coupler 121 undergoes TIR until it is outcoupled (e.g., projected (e.g., reflected or transmitted)) to the first detector 312 or the second detector 316.

[0047] For an MTF metric, processing one or more images of the plurality of first images or the plurality of second images includes comparing an outer edge of one or more portions of the one or more calibration images to same outer edges of the same one or more portions of the plurality of first images or the one or more images of the plurality of second images.

[0048] The plurality of first metrics includes an eyebox metric. For the eyebox metric, during capture of the plurality of first images or during capture of the plurality of second images, the first detector 312 or the second detector 316 is moved to scan across a plurality of locations along the output coupler 122 of the optical device 100. Processing one or more of the plurality of first images or the plurality of second images includes comparing different images corresponding to different field areas of the output coupler 122. For the eyebox metric, the first light beam B1 incoupled to the input coupler 121 undergoes TIR until the incoupled first light beam B1 is outcoupled (e.g., projected (e.g., reflected or transmitted)) to the first detector 312 or the second detector 316.

[0049] The plurality of first metrics includes a ghost image metric. For the ghost image metric, a calibration light beam is directed from the first light engine 310 toward the second detector 316 prior to the capture of the plurality of first images and the capture of the plurality of second images. While the second detector 316 is displaced from the optical device 100, the second detector 316 captures one or more calibration images of the calibration light beam. The second detector 316 may be in a calibration position shown by the dashed line in FIG. 4A and aligned with the first light engine 310, while the optical device 100 may be positioned away from the second detector 316 (as shown by the dashed line for the optical device 100 in FIG. 4A) so as to be out of the field of view of the second detector 316 and the first light engine 310. The second detector 316 may then be positioned to be aligned with the first detector 312. In one embodiment, which can be combined with other embodiments, the second image is captured before capturing the first image.

[0050] For the ghost image metric, processing one or more of the plurality of first images or the plurality of second images includes comparing the one or more calibration images to one or more of the plurality of first images or the plurality of second images to determine an offset between the one or more calibration images and the one or more of the plurality of first images or the plurality of second images. In one embodiment, which can be combined with other embodiments, the offset is an offset between a light pattern design (such as a reticle) in the one or more calibration images and a light pattern design (such as a reticle) in the first image or the second image.

[0051] 4B is a schematic diagram of a configuration 400B of the first subsystem 202 shown in FIG. 2 and FIG. 3A according to one embodiment. The configuration 400B includes a first light engine 310, a first detector 312, and a second detector 316. The first light engine 310 includes a first light source 402, a first projection structure 404, and a first lens 406. The first light engine 310 of the configuration 400B includes one or more two-dimensional galvanometer mirrors 408 (such as an array of two-dimensional galvanometer mirrors) configured to rotate a first light beam emitted by the first projection structure 404 along a 90 degree rotation toward the stage path 211. In the embodiment shown in FIG. 4B, the first projection structure 404 and the first lens 406 are oriented perpendicular to the stage path 211.

[0052] The first detector 312 includes a second lens 410 and a first camera 412. The second detector 316 includes a third lens 414 and a second camera 416. The first light engine 310 rotates the first light beam B1 90 degrees using one or more 2D galvanometer mirrors 408 toward the stage path 211 and toward the input coupler 121 of the optical apparatus 100.

[0053] 4B, a first lens 406 is positioned between the first illuminator 401 and the stage path 211 along the optical path from the first illuminator to the stage path 211. One or more 2D galvanometer mirrors 408 are positioned along the optical path between the first lens 406 and the stage path 211. The optical path includes a 90 degree turn.

[0054] Figure 4C is a schematic diagram of a configuration 400C of the first subsystem 202 shown in Figures 2 and 3A, according to one embodiment. Configuration 400C is similar to configuration 400A shown in Figure 4A and includes one or more of its aspects, features, components, and / or properties.

[0055] Configuration 400C includes an alignment module 494. Alignment module 494 is shown in relation to first light engine 310 to align first projection structure 404 and first lens 406. Alignment module 494 includes a laser source 495, a beam splitter 496, and an alignment detector 497. Alignment module 494 includes a pinhole 498 formed in plate 499. Alignment detector 497 may include a camera. Alignment module 494 may be used in addition to alignment detector 308.

[0056] The alignment module 494 is used to perform an alignment process. In the alignment process, the first light source 402, the first projection structure 404, and the first lens 406 are moved out of position from the input coupler 121 of the optical device 100. The alignment module 494 uses a laser source 495 to direct a first laser light L1 through a pinhole 498 toward the optical device 100. Using an alignment detector 497, the light intensity of the first reflected laser light RL1 is determined. The first reflected laser light RL1 is that first laser light L1 reflected from the optical device 100. The first reflected laser light RL1 is directed to the alignment detector 497 using a beam splitter 496. The tilt and pitch of the laser source 495 are adjusted to increase the light intensity to an increased light intensity. A first position of the first reflected laser light RL1 received by the alignment detector 497 is determined at the increased light intensity. The first position is the position of the first reflected laser light RL1 in the image where the alignment detector 497 captures the first reflected laser light RL1.

[0057] In the alignment step, the first lens 406 is moved to be aligned with the input coupler 121 of the optical device 100 (as shown by the dashed line in FIG. 4C ), and the second laser light is directed through the pinhole 498 towards the first lens 406. The tilt and pitch of the first lens 406 are adjusted until the second position of the second reflected laser light received by the alignment detector matches the first position of the first reflected laser light RL1. The second reflected laser light is the second laser light that reflects from the first lens 406 back towards the beam splitter 496.

[0058] In the alignment step, the first projection structure 404 is moved to be aligned with the input coupler 121 of the optical device 100 (as shown by the dashed line in FIG. 4C ), and the third laser light is directed through the pinhole 498 towards the first projection structure 404. The tilt and pitch of the first projection structure 404 are adjusted until the third position of the third reflected laser light received by the alignment detector matches the first position of the first reflected laser light RL1. The third reflected laser light is the third laser light that reflects from the first projection structure 404 back towards the beam splitter 496.

[0059] The alignment module 494 may then be moved out of alignment with the input coupler 121 of the optical device 100, and the first light source 402 may be moved into alignment with the input coupler 121 of the optical device 100. The lenses, projection structure, and camera may be aligned using the alignment module 494 and the alignment process to facilitate accurate processes such as accurate determination of metrics of the optical device 100. The steps described for the alignment process may be combined with methods 1000, 1100, 1200 described below.

[0060] 4D is a schematic diagram of a configuration 400D of the first subsystem 202 shown in FIG. 2 and FIG. 3A according to one embodiment. The configuration 400D includes a first light engine 310, a first detector 312, and a second detector 316. The first light engine 310 includes a first lens 406a positioned between the first light source 402, the first projection structure 404, the first illuminator 401, and a lens 406b positioned between the first lens 406a and the stage path 211. The first light engine 310 includes an adjustable aperture 407 positioned between the lens 406b and the first lens 406a. The adjustable aperture 407 can be formed in a plate 415. The adjustable aperture 407 can be adjusted by moving the adjustable aperture 407 up and down (such as by moving the plate 415) and / or opening and closing the adjustable aperture 407.

[0061] The first light engine 310 may include one or more devices 413 shown in FIG. 4A positioned between the lens 406b and the stage path 211. The first detector 312 includes a second lens 410 and a first camera 412. The second detector 316 includes a third lens 414 and a second camera 416. In one embodiment, which can be combined with other embodiments, each of the first lens 406, the first lens 406a, the lens 406b, the second lens 410, and / or the third lens 414 is formed with the same convex lens structure having the same radius of curvature. Each of the first lens 406, the first lens 406a, the lens 406b, the second lens 410, and / or the third lens 414 has the same lens structure. Using the same lens structure for the lenses facilitates compensation for optical aberrations, such as aberrations of light reflection and / or transmission.

[0062] 4E is a schematic diagram illustrating a configuration 400E of the second subsystem 204 shown in FIG. 2 and FIG. 3B according to one embodiment. The configuration 400E includes a second light engine 360 ​​and a face illumination detector 318. The second light engine 360 ​​includes a second illuminator 461 and a fourth lens 466 positioned between the second illuminator 461 and the stage path 211. The second illuminator 461 includes a second light source 462 and a second projection structure 464. The second projection structure 464 and the fourth lens 466 are oriented parallel to the stage path 211.

[0063] The second projection structure 464 includes one or more of a display and / or a reticle. In one embodiment that can be combined with other embodiments, the second projection structure 464 includes one or more of a microdisplay, a spatial light modulator (SLM), and / or a reticle. In one example that can be combined with other examples, the SLM includes one or more of a digital micromirror device (DMD) and / or a liquid crystal on silicon (LCOS) emitter.

[0064] The face illumination detector 318 includes a third camera 426, a fifth lens 424 positioned between the third camera 426 and the stage path 211, and an eyebox blocker 420 positioned between the fifth lens 424 and the stage path 211. The eyebox blocker 420 is adjacent to a face level 422.

[0065] The optical device 100 is positioned to align the input coupler 121 with the second light engine 360 ​​and align the output coupler 122 with the face illumination detector 318. A second light beam B2 is directed from the second light engine 360 ​​towards the input coupler 121 of the optical device 100. The face illumination detector 318 captures a number of third images (in addition to the first and second images described in connection with FIG. 4A ) of a third projected light beam BP3 projected from the output coupler 122 of the optical device 100.

[0066] The plurality of third images include a third projected light ray BP3 that is projected from the output coupler 122 of the optical device 100 and passes through the eyebox blocker 420 of the face illumination detector 318. The plurality of third images are processed (such as by using the controller 208) to determine one or more second metrics of the optical device. The one or more second metrics include a view leakage metric.

[0067] 2 and 3C , according to one embodiment. The third subsystem 206 includes a first light engine 310 mounted above the stage path 211 and configured to direct an upper light beam toward the stage path 211, and a second light engine 322 mounted below the stage path 211 and configured to direct a lower light beam toward the stage path 211.

[0068] Configuration 400F includes a detector 320 mounted above the stage path 211 and configured to receive a projected light beam projected from the stage path 211. The projected light beam is projected from the optical arrangement 100. The first light engine 310 includes a first illuminator 401 and a first lens 406. The detector 320 includes a second lens 410 and a first camera 412. The second light engine 322 includes a device and a third lens.

[0069] The second light engine 322 includes a second illuminator 471 and a second lens 476 positioned between the second illuminator 471 and the stage path 211. The second illuminator 471 includes a second light source 472 and a second projection structure 474. The second projection structure 474 is a display or a reticle. In one embodiment, which can be combined with other embodiments, configuration 400F is used to obtain a see-through transmittance metric of the optical device 100 by illuminating an output coupling grating of the optical device 100 with a bottom beam emitted by the second light engine 322.

[0070] As shown in FIG. 4F, the input coupler 121 of the optical device 100 is aligned with the first light engine 310, and the output coupler 122 is aligned with the second light engine 322. The detector 320 is aligned (e.g., vertically) with the second light engine 322 and offset from the first light engine 310. The second light engine 322 directs a first light beam LB1 toward the output coupler 122. An upper light beam LB2 may be directed from the first light engine 310 toward the input coupler 121 of the optical device 100. Using the detector 320, a plurality of first images of the first light beam LB1 transmitted through the output coupler 122 and projected from the output coupler 122 as a first projected beam PB1 are captured. The optical device 100 is positioned away from the second light engine 322 (the optical device 100 is shown in dashed lines in FIG. 4F ) to position the optical device 100 outside the field of view of the second light engine 322 and the detector 320. The second light beam is directed from the second light engine 322 towards the detector 320. The detector captures a plurality of second images of the second light beam projected from the waveguide coupler as second projected beams. The first image and the second image are full-field images. The first light beam and the second light beam are emitted from the light engine in the red spectrum, the green spectrum, and the blue spectrum (e.g., sequentially). The plurality of first images and the plurality of second images capture the first light beam and the second light beam in the red spectrum, the green spectrum, and the blue spectrum, respectively. In one embodiment, which can be combined with other embodiments, the second image is captured before the first image.

[0071] The second image is compared (e.g., by using controller 208) to the first image to determine a see-through transmittance metric of optical device 100. In one embodiment, which can be combined with other embodiments, the comparing includes comparing a second light intensity of the plurality of second images to a first light intensity of the plurality of first images.

[0072] 4G is a schematic diagram of a configuration 400G of the third subsystem 206 shown in FIG. 2 and FIG. 3C according to one embodiment. The configuration 400G includes a detector 320 and a first light engine 310. The configuration 400G includes a patterned substrate 490 positioned below the stage path 211. The patterned substrate 490 includes a pattern design formed thereon. Each of the first light engine 310, the patterned substrate 490, and the detector 320 are positioned within the third body 201C of the third subsystem 206. In one embodiment, which can be combined with other embodiments, the patterned substrate 490 includes one or more of a plurality of protrusions 493 and / or a plurality of recesses 489 (shown in dashed lines in FIG. 4G) that form the pattern design.

[0073] 4G, the patterned substrate 490 is at least partially aligned below the detector 320, and the patterned substrate 490 is at least partially offset from the first light engine 310. The optical arrangement 100 below the detector 320 aligns the optical arrangement 100 with the detector 320, and the optical arrangement 100 is positioned above the patterned substrate 490 at a distance D1 from the patterned substrate 490.

[0074] The patterned substrate 490 directs a bottom light ray 491 towards the optical device 100. The bottom light ray 491 is reflected from the top surface of the patterned substrate 490 towards the optical device 100. The bottom light ray 491 is transmitted through the optical device 100 and captured using the detector 320. In one embodiment that can be combined with other embodiments, the patterned substrate 490 reflects ambient light as the bottom light ray 491. In one embodiment that can be combined with other embodiments, the patterned substrate 490 reflects light from a light engine, such as the second light engine 322. In one embodiment that can be combined with other embodiments, the configuration 400G includes a second light engine 322 configured to direct a light ray towards the patterned substrate 490, where the patterned substrate 490 reflects a light ray from the second light engine 322 as the bottom light ray 491. The first light engine 310 includes a first light source 402, a first projection structure 404, and a first lens 406. The detector 320 includes a second lens 410 and a first camera 412.

[0075] While the patterned substrate 490 is partially aligned with and partially displaced from the detector 320 (as shown in FIG. 4G ), the detector 320 captures a plurality of first images of the projected light beam 492 projected from the output coupler 122 of the optical apparatus 100. The plurality of first images capture a red spectrum, a green spectrum, and a blue spectrum of the projected light beam 492. The plurality of first images are processed (e.g., by the controller 208) to determine one or more see-through metrics of the optical apparatus 100.

[0076] The one or more see-through metrics include a see-through flare metric. For the see-through flare metric, the optical device 100 is positioned below the first light engine 310 to align the input coupler 121 of the optical device 100 with the first light engine 310. A first light beam LB3 is directed from the first light engine 310 toward the input coupler 121 of the optical device 100. In such an embodiment, the projected light beam 492 includes the first light beam LB3 from the first light engine 310 and a bottom light beam 491 reflected from the patterned substrate 490. The first light beam LB3 is emitted from the first light engine 310 with a light pattern design different from the pattern design of the patterned substrate 490.

[0077] The one or more see-through metrics include one or more of a see-through distortion metric and / or a see-through transmittance metric. For the see-through distortion metric and / or the see-through transmittance metric, the projected light beam 492 includes a light beam 491 reflected from the patterned substrate 490. The optical device 100 is positioned away from the detector 320 to offset the position of the optical device 100 from the detector 320 and the patterned substrate 490 (shown in dashed lines for the optical device 100 in FIG. 4G) and position the optical device 100 out of the field of view of the patterned substrate 490 and the detector 320. The detector 320 captures a plurality of second images of the reflected light beam reflecting from the patterned substrate 490 towards the detector 320. The plurality of second images capture the reflected light beam in the red spectrum, the green spectrum, and the blue spectrum. Processing the plurality of first images includes comparing the plurality of second images to the plurality of first images to determine a see-through distortion metric and / or a see-through transmittance metric. In one embodiment, which can be combined with other embodiments, the second image is captured prior to capturing the first image.

[0078] The one or more see-through metrics include a see-through ghost image metric. For the see-through ghost image metric, the optical device 100 is positioned away from the detector 320 to offset the position of the optical device 100 from the detector 320 and the patterned substrate 490. The detector 320 captures a plurality of second images of the reflected light beam reflected from the patterned substrate 490 with the detector 320. The plurality of second images capture reflected light beams of red, green, and blue spectra. Processing the plurality of first images includes determining an offset between the plurality of second images and the plurality of first images. In one embodiment, which can be combined with other embodiments, the offset is an offset between a pattern design (such as a reticle) in the first image and a pattern design (such as a reticle) in the second image.

[0079] 5 is a schematic diagram of an image 500 according to one embodiment. Image 500 includes a light pattern design (such as a reticle) having dark areas 501 and light areas 502. Image 500 can be used to determine contrast and / or angular uniformity metrics.

[0080] For the angular uniformity metric, the process includes comparing one or more first portions 502a of the light pattern design to one or more second portions 502b, 502c of the light pattern design in the image 500. The first and second portions 502a, 502b, 502c correspond to bright areas 502. The process includes comparing the light intensity of the one or more first portions 502a to the light intensity of the one or more second portions 502b, 502c. The portions 502a, 502b, 502c are disposed at different radii with respect to the center of the image 500.

[0081] For the contrast metric, the process involves comparing the light intensity of one or more light portions 502a of the light pattern design in the image 500 to the light intensity of one or more dark portions 501a of the light pattern design in the image 500. The light portions 502a have a light intensity I1 and the dark portions 501a have a light intensity I2. The contrast metric may be determined and expressed as "C" according to Equation 1 below: TIFF0007621474000001.tif13170

[0082] 6A-6C are schematic diagrams of images 610, 620, 630 according to one embodiment. FIG. 6A shows a red image 610, FIG. 6B shows a green image 620, and FIG. 6C shows a blue image 630. The images 610, 620, 630 are used to determine a color uniformity metric. The process involves comparing the images 610, 620, 630 using the same field area in each respective image 610, 620, 630. The same field area includes one or more bright areas 602a-602c, 603a-603c at the same location in each image 610, 620, 630. The color uniformity metric can represent a ratio of light intensity of one or more bright areas 602a-602c, 603a-603c in each image 610, 620, 630.

[0083] Figures 7A-7C are schematic diagrams of images 710, 720, 730 according to one embodiment. Figure 7A shows a calibration image 710, Figure 7B shows a first image (e.g., a reflected image), and Figure 7C shows a second image (e.g., a transmitted image). Images 710, 720, 730 can be used to determine an efficiency metric.

[0084] The process includes comparing the calibration image 710 to a first image 720 and a second image 730 using the same field area in each respective image 710, 720, 730. The same field area includes one or more bright portions 702a-702c at the same location in each image 710, 720, 730. The process includes comparing the light intensities of the one or more bright portions 702a-702c in the images 710, 720, 730. The calibration image 710 includes a light intensity IC1 of the bright portion 702a, the first image 720 includes a light intensity IR1 of the bright portion 702b, and the second image 730 includes a light intensity IT1 of the bright portion 702c.

[0085] The efficiency metric may be determined and expressed as "E" in Equation 2 below. TIFF0007621474000002.tif14170

[0086] 8 is a schematic diagram of an image 800 according to one embodiment. The image 800 includes a light pattern design (such as a reticle) having dark and bright areas. The image 800 can be used to determine an MTF metric. The processing includes comparing an edge area 832 of the one or more calibration images with the same edge area (e.g., the same location in the image) of the same one or more portions of the plurality of first images or one or more of the plurality of second images. The edge area 832 at least partially encompasses an outer edge 831 of the one or more portions (such as the bright areas).

[0087] 9A-9C are schematic diagrams of images 910, 920, 930 according to one embodiment. Each of the images 910, 920, 930 shows a light pattern design that can be used for light directed by the first light engine 310, the first light engine 370, the second light engine 360, the first light engine 370, the second light engine 380, the second light engine 322, and / or the patterned substrate 490. Each of the images 910, 920, 930 can be used to determine a ghost image metric and / or other metrics (such as other first metrics). Each of the images 910, 920, 930 includes a plurality of dark portions 901a-901c and a plurality of light portions 902a-902c.

[0088] FIG. 10 is a schematic block diagram of a method 1000 for analyzing an optical device, according to one embodiment.

[0089] Step 1002 of method 1000 includes positioning an optical device within a first subsystem to align the optical device with a first detector and a second detector of the first subsystem.

[0090] Step 1004 includes directing a first light beam from a first light engine of the first subsystem toward an optical device. In one embodiment, which can be combined with other embodiments, the directing includes rotating the first light beam 90 degrees toward the stage path.

[0091] Step 1006 includes capturing a plurality of first images of the first projected light beam projected from the optical device using a first detector of the first subsystem.

[0092] Step 1008 includes capturing a plurality of second images of the second projected light beam projected from the optical device using a second detector of the first subsystem.

[0093] Step 1010 includes processing one or more of the plurality of first images or the plurality of second images to determine a plurality of first metrics of the optical device, including an angular uniformity metric, a contrast metric, an efficiency metric, a color uniformity metric, a modulation transfer function (MTF) metric, a field of view (FOV) metric, a ghost image metric, and / or an eyebox metric.

[0094] Step 1012 includes positioning an optical device within the second subsystem to align the optical device with a face illumination detector of the second subsystem.

[0095] Step 1014 includes directing a second light beam from a second light engine of the second subsystem toward an optical device.

[0096] Step 1016 includes capturing a plurality of third images of the third projected light beam projected from the optical device using a face illumination detector of the second subsystem.

[0097] Step 1018 includes processing the plurality of third images to determine one or more second metrics of the optical arrangement. The one or more second metrics include a view leakage metric.

[0098] FIG. 11 is a schematic block diagram of a method 1100 for analyzing an optical device, according to one embodiment.

[0099] Step 1102 of method 1100 includes positioning an optical device over a light engine to align the optical device with the light engine.

[0100] Step 1104 includes directing a first light beam from the light engine towards an optical device.

[0101] Step 1106 includes capturing, using a detector, a plurality of first images of the first light beam projected from the optical device as the first projected light beam.

[0102] Step 1108 includes positioning the optical device away from the light engine to offset the optical device from the light engine.

[0103] Step 1110 includes directing a second beam of light from the light engine towards a detector.

[0104] Step 1112 includes capturing a plurality of second images of the second light beam.

[0105] Step 1114 includes comparing the plurality of second images to the plurality of first images to determine a see-through transmittance metric of the optical device.

[0106] FIG. 12 is a schematic block diagram of a method 1200 for analyzing an optical device, according to one embodiment.

[0107] Step 1202 of method 1200 includes positioning an optical device below a detector to align the optical device with the detector.

[0108] Step 1204 includes positioning an optical device above the patterned substrate at a distance from the patterned substrate, the patterned substrate including the pattern design formed thereon.

[0109] Step 1206 includes capturing a plurality of first images of the projected light beam projected from the optical arrangement using a detector while the patterned substrate is at least partially aligned with the detector.

[0110] Step 1208 includes processing the plurality of first images to determine one or more see-through metrics of the optical device, including one or more of a see-through transmittance metric, a see-through distortion metric, a see-through flare metric, and / or a see-through ghost image metric.

[0111] Advantages of the present disclosure include the use of a single optical device metrology system 200 to determine several metrology metrics (such as a view leakage metric, one or more see-through metrics, and one or more other metrology metrics) of multiple optical devices (such as waveguide couplers) on a single system using a single stage path 211. In one embodiment, which can be combined with other embodiments, a single system using a single stage path 211 can be used to determine a view leakage metric, an angular uniformity metric, a contrast metric, an efficiency metric, a color uniformity metric, a modulation transfer function (MTF) metric, a field of view (FOV) metric, a ghost image metric, an eyebox metric, a see-through distortion metric, a see-through flare metric, a see-through ghost image metric, and a see-through transmittance metric. Advantages also include increased throughput, reduced delays and costs, and increased efficiency. Throughput is increased through the use of a feed system connected to each subsystem of the optical device metrology system.

[0112] It is contemplated that one or more aspects disclosed herein may be combined. By way of example, one or more aspects, features, components, and / or characteristics of optical device metrology system 200, first subsystem 202, second subsystem 204, third subsystem 206, configuration 400A, configuration 400B, configuration 400C, configuration 400D, configuration 400E, configuration 400F, configuration 400G, image 500, images 610-630, images 710-730, image 800, images 910-930, method 1000, method 1100, and / or method 1200 may be combined. By way of example, one or more of the steps described in connection with optical device metrology system 200, subsystems 202, 204, 206, and / or configurations 400A-400G may be combined with one or more of the steps described in connection with method 1000, method 1100, and / or method 1200. Moreover, it is contemplated that one or more of the embodiments disclosed herein may include some or all of the above advantages.

[0113] While the above description is directed to embodiments of the present disclosure, other and further embodiments of the disclosure may be devised without departing from the basic scope of the disclosure, the scope of which is determined by the claims that follow.

Claims

1. a stage configured to convey the tray along a stage path; a first light engine mounted above the stage path and configured to direct an upper light beam toward the stage path; a second light engine mounted below the stage path and configured to direct a lower light beam toward the stage path; a detector mounted above the stage path and configured to receive a projected light beam projected from the stage path; a controller in communication with the stage, the first light engine, the second light engine, and the detector, the controller, when executed, performing: causing the stage to position an optical device supported on the tray above the second light engine to align the optical device with the second light engine; causing the second light engine to direct a first light beam from the second light engine towards the optical device; causing the detector to capture a plurality of first images of the first light beam projected from the optical device as a first projected light beam; causing the stage to position the optical device away from the second light engine to offset the optical device from the second light engine; causing the second light engine to direct a second light beam from the second light engine towards the detector; causing the detector to capture a plurality of second images of the second light beam; comparing the plurality of second images to the plurality of first images to determine a see-through transmittance metric of the optical device; A controller including instructions to An optical device measurement system comprising:

2. 2. The optical device metrology system of claim 1 , wherein the upper and lower light rays are emitted from the first and second light engines in a red spectrum, a green spectrum, and a blue spectrum, and the first and second images capture the first and second light rays in the red spectrum, the green spectrum, and the blue spectrum, respectively.

3. 3. The optical device metrology system of claim 2, wherein the second light engine comprises an illuminator and a lens positioned between the illuminator and the stage path, the illuminator comprising a light source and a projection structure, the projection structure comprising one or more of a microdisplay, a spatial light modulator (SLM), or a reticle.

4. The optical device metrology system of claim 3 , wherein the detector comprises a camera and a lens positioned between the camera and the stage path.

5. a stage configured to carry a tray configured to support an optical device along a stage path; a first light engine mounted above the stage path and configured to direct an upper light beam toward the stage path; a second light engine mounted below the stage path and configured to direct a lower light beam toward the stage path; a detector mounted above the stage path and configured to receive a projected light beam projected from the stage path, the detector aligned with the second light engine and offset from the first light engine; a controller in communication with the first light engine, the second light engine, and the detector, the controller including instructions, when executed, that use results from the detector to determine a see-through transmittance metric of the optical device supported on the tray; An optical device measurement system comprising:

6. The optical device metrology system of claim 5 further comprising a body having a first opening and a second opening for allowing the stage to move through the first opening and the second opening.

7. The optical device metrology system of claim 6 , wherein each of the first light engine, the second light engine, and the detector are positioned within the body.

8. The optical device measurement system of claim 5, wherein the first light engine comprises a first illuminator and a first lens positioned between the first illuminator and the stage path, and the first illuminator comprises a first light source and a first projection structure.

9. The optical device metrology system of claim 8 , wherein the first projection structure comprises one or more of a microdisplay, a spatial light modulator (SLM), or a reticle.

10. 9. The optical device metrology system of claim 8, wherein the second light engine comprises a second illuminator and a second lens positioned between the second illuminator and the stage path, the second illuminator comprising a second light source and a second projection structure.

11. The optical device metrology system of claim 10 , wherein the second projection structure comprises one or more of a microdisplay, a spatial light modulator (SLM), or a reticle.

12. The optical device metrology system of claim 10 , wherein the detector comprises a camera and a third lens positioned between the camera and the stage path.

13. positioning an optical device above the light engine to align the optical device with the light engine; Directing a first light beam from the light engine towards the optical device; capturing a plurality of first images of the first light beam projected from the optical device as a first projected light beam using a detector; positioning the optical device away from the light engine to offset the optical device from the light engine; directing a second beam of light from the light engine towards the detector; capturing a plurality of second images of the second light beam; comparing the plurality of second images to the plurality of first images to determine a see-through transmittance metric of the optical device; 16. A method for analyzing an optical device, comprising:

14. 14. The method of claim 13, wherein the first light beam and the second light beam are emitted from the light engine in a red spectrum, a green spectrum, and a blue spectrum.

15. 15. The method of claim 14, wherein the plurality of first images and the plurality of second images capture the first light rays and the second light rays in the red spectrum, the green spectrum, and the blue spectrum, respectively.

16. The method of claim 13 , wherein an output coupler of the optical device is positioned above the light engine to align the output coupler with the light engine.

17. 17. The method of claim 16, further comprising directing an upper light beam from an upper light engine towards an input coupler of the optical device, the upper light engine being positioned above the optical device.

18. 17. The method of claim 16, further comprising aligning the detector with the light engine prior to directing the first light beam.

19. The method of claim 13 , wherein the comparing comprises comparing a second light intensity of the plurality of second images to a first light intensity of the plurality of first images.

Images