CN116710744A

CN116710744A - Optical resolution measuring method for optical device

Info

Publication number: CN116710744A
Application number: CN202180081206.XA
Authority: CN
Inventors: 傅晋欣; 孙阳阳; 卢多维克·戈代
Original assignee: Applied Materials Inc
Current assignee: Applied Materials Inc
Priority date: 2020-11-24
Filing date: 2021-11-23
Publication date: 2023-09-05

Abstract

Embodiments herein provide a method of determining an optical device Modulation Transfer Function (MTF). The methods described herein include projecting a baseline image of a pattern from a light engine to a detector. The baseline image is analyzed to determine a baseline function. A baseline Fast Fourier Transform (FFT) or baseline MTF of the baseline function is taken. The method further includes projecting an image of the pattern from the light engine to one or more optical devices. The pattern is outcoupled from the one or more optical devices to the detector. The image is analyzed to determine a function. Corresponding to the image acquisition function FFT or function MTF. The optical device MTF of the one or more optical devices is determined by comparing the baseline FFT to the functional FFT determined by analyzing the image or by comparing the baseline MTF to the functional MTF determined by analyzing the image.

Description

Optical resolution measuring method for optical device

Technical Field

Embodiments of the present disclosure generally relate to optical devices. More particularly, embodiments described herein provide methods of determining a Modulation Transfer Function (MTF) of an optical device.

Background

Virtual reality is generally considered a computer-generated simulated environment in which a user has a significant physical presence. The virtual reality experience can be generated in 3D form and viewed with a Head Mounted Display (HMD), such as glasses or other wearable display device having a near-eye display panel as a lens, to display a virtual reality environment that replaces the actual environment.

However, the augmented reality enabled experience allows the user to view the surrounding environment while still being able to see through the display lenses of the glasses or other HMD device, and also see the virtual object imagery generated for display and rendering as part of the environment. Augmented reality can include any type of input, such as audio and tactile input, as well as virtual imagery, graphics, and video that enhances or augments the environment experienced by the user. As an emerging technology, augmented reality has many challenges and design limitations.

One such challenge is determining the optical resolution of the optical device to ensure compliance with image quality standards. Current measurement systems for optical devices generally have low sampling rates and low throughput across large fields of view, and do not adequately compensate for defects in image quality caused by cameras and image projectors within the measurement system. Additionally, the measurement system may be bulky and susceptible to defects associated with the image projector of the measurement system. It is therefore desirable to have a system and method for optical resolution measurement that will not be affected by the defects associated with image projectors or cameras and will have improved throughput. Accordingly, what is needed in the art is a method of determining the MTF of an optical device.

Disclosure of Invention

In one embodiment, a method is provided. The method includes projecting a baseline image of the pattern. The baseline image is projected from the light engine of the measurement system. The measurement system includes a stage disposed below the light engine. The stage is operable to have one or more optical devices disposed thereon. The light engine disposed above the stage projects the baseline image to the one or more optical devices. The measurement system further includes a detector oriented to face the stage. The method further includes capturing the baseline image. The baseline image is captured by the detector. The method further includes analyzing the baseline image to locate a first plurality of points on the baseline image. The first plurality of points is converted to a baseline function. The method further includes taking a baseline Fast Fourier Transform (FFT) of the baseline function and disposing the one or more optical devices on the stage. The method further includes projecting an image of the pattern from the light engine to the one or more optical devices and capturing the image. The image is captured by the detector. The method further includes analyzing the image to locate a second plurality of points on the image. The second plurality of points is converted into a function. The method further includes obtaining a functional FFT corresponding to the image, and determining an optical device Modulation Transfer Function (MTF) of the one or more optical devices by comparing the baseline FFT to the functional FFT corresponding to the image.

In another embodiment, a method is provided. The method includes projecting a baseline image of the pattern. The baseline image is projected from the light engine of the measurement system. The measurement system includes a stage disposed below the light engine. The stage is operable to have one or more optical devices disposed thereon. The light engine disposed above the stage projects the baseline image to the one or more optical devices. The measurement system further includes a detector oriented to face the stage. The method further includes taking a baseline Fast Fourier Transform (FFT) corresponding to the baseline image and projecting an image of the pattern to the one or more optical devices. The image is projected from the light engine to the one or more optical devices. The method further includes capturing the image. The image is captured by the detector. The method further includes obtaining a functional FFT corresponding to the image, and determining an optical device Modulation Transfer Function (MTF) of the one or more optical devices by comparing the baseline FFT to the functional FFT corresponding to the image.

In yet another embodiment, a method is provided. The method includes projecting a baseline image of the pattern from the light engine to a detector of the measurement system. The method further includes capturing the baseline image by the detector and analyzing the baseline image to determine a baseline Fast Fourier Transform (FFT). The method further includes projecting an image of the pattern from the light engine to one or more optical devices. The image is projected to the detector by the one or more optical devices. The method further includes capturing the image by the detector and analyzing the image. The method further includes determining an optical device Modulation Transfer Function (MTF) of the one or more optical devices.

Drawings

So that the manner in which the above recited features of the present disclosure can be understood in detail, a more particular description of the disclosure, briefly summarized above, may be had by reference to embodiments, some of which are illustrated in the appended drawings. It is to be noted, however, that the appended drawings illustrate only exemplary embodiments and are therefore not to be considered limiting of its scope, for the invention may admit to other equally effective embodiments.

Fig. 1A is a perspective front view of a substrate according to embodiments described herein.

Fig. 1B is a perspective front view of an optical device according to embodiments described herein.

Fig. 2 is a schematic cross-sectional view of a measurement system according to embodiments described herein.

Fig. 3 is a flow chart of a method for determining a Modulation Transfer Function (MTF) of an optical device according to embodiments described herein.

Fig. 4 is a schematic diagram of a system during a method of determining a Modulation Transfer Function (MTF) of an optical device.

To facilitate understanding, identical reference numerals have been used, where possible, to designate identical elements that are common to the figures. It is contemplated that elements and features of one embodiment may be beneficially incorporated in other embodiments without further recitation.

Detailed Description

Embodiments of the present disclosure generally relate to optical devices. More particularly, embodiments described herein provide methods of determining a Modulation Transfer Function (MTF) of an optical device. The method includes projecting a baseline image of the pattern. The baseline image is projected from a light engine of the measurement system. The measurement system includes a stage disposed below the light engine. The stage is operable to have one or more optical devices disposed thereon. The light engine disposed above the stage projects the baseline image to the one or more optical devices. The measurement system further includes a detector oriented to face the stage. The method further includes capturing the baseline image. The baseline image is captured by the detector. The method further includes analyzing the baseline image to locate a first plurality of points on the baseline image. The first plurality of points is converted to a baseline function. The method further includes taking a baseline FFT or baseline MTF of the baseline function, and disposing the one or more optical devices on the stage. The method further includes projecting an image of the pattern from the light engine to the one or more optical devices and capturing the image. The image is captured by the detector. The method further includes analyzing the image to locate a second plurality of points on the image. The second plurality of points is converted into a function. The method further includes obtaining a functional FFT or functional MTF corresponding to the image, and determining an optics MTF of the one or more optics by comparing the baseline FFT to the functional FFT or by comparing the baseline MTF to the functional MTF.

Fig. 1A is a perspective front view of a substrate 101 according to embodiments described herein. The substrate includes a plurality of optical devices 100 disposed on a surface 103 of a substrate 101. The optical device 100 is a waveguide combiner for virtual reality, augmented reality, or mixed reality. In some embodiments, which can be combined with other embodiments described herein, the optical device 100 is a flat optical device, such as a metasurface (metasurface).

The substrate 101 can be any substrate used in the art and can be opaque or transparent to the selected laser wavelength depending on the use of the substrate 101. Additionally, the substrate 101 may have different shapes, thicknesses, and diameters. For example, the substrate 101 may have a diameter of about 150mm to about 300 mm. The substrate 101 may have a circular, rectangular, or square shape. The substrate 101 may have a thickness of between about 300 μm to about 1 mm. Although only nine optical devices 100 are shown on the substrate 101, any number of optical devices 100 may be provided on the surface 103.

Fig. 1B is a perspective front view of the optical device 100. It will be appreciated that the optical device 100 described herein is an exemplary optical device and that other optical devices may be used or modified to achieve aspects of the present disclosure. The optical device 100 includes a plurality of optical device structures 102 disposed on a surface 103 of a substrate 101. The optical device structure 102 may be a nanostructure having sub-micron dimensions (e.g., nano-sized dimensions). The area of the optic structure 102 corresponds to one or more gratings 104, such as a first grating 104a, a second grating 104b, and a third grating 104c. In some embodiments, which can be combined with other embodiments described herein, the optical device 100 includes at least a first grating 104a corresponding to the in-coupling grating and a third grating 104c corresponding to the out-coupling grating. In some embodiments, which can be combined with other embodiments described herein, the optical device 100 also includes a second grating 104b corresponding to the intermediate grating. The optic structure 102 may be angled or binary. The optic structure 102 may have other shapes including, but not limited to, circular, triangular, elliptical, regular polygonal, irregular polygonal, and/or irregularly shaped cross-sections.

In operation, the first grating 104a receives an incident light beam (virtual image) having an intensity from a light source. The incident beam is split by the optics structure 102 into a T1 beam having the full intensity of the incident beam to direct the virtual image to the intermediate grating (if used) or the third grating 104c. In some embodiments, which can be combined with other embodiments described herein, the T1 beams undergo Total Internal Reflection (TIR) by the optical device 100 until the T1 beams contact the optical device structure 102 of the intermediate grating. The intermediate grating's optics structure 102 diffracts these T1 beams into T-1 beams, which undergo TIR through the optics 100 to the third grating's 104c optics structure 102. The optics structure 102 of the third grating 104c outcouples (outcover) these T-1 beams to the user's eyes to modulate the field of view of the virtual image generated from the light source from the user's perspective and further increase the viewing angle from which the user can view the virtual image. In other embodiments (which can be combined with other embodiments described herein), the T1 beams undergo TIR by the optical device 100 until these T1 beams contact the optical device structure 102 of the third grating 104c and are outcoupled to modulate the field of view of the virtual image generated from the light source.

To ensure that the optical device 100 meets the image quality standard, the optical device MTF of the optical device 100 is obtained. In some embodiments, the optics MTF provides image quality information regarding image resolution and image contrast. The embodiments of the measurement system 200 described herein provide the ability to achieve an optical device MTF with increased throughput and better quality control. Additionally, embodiments of the measurement system 200 described herein provide the ability to acquire the optical device MTF such that the measured optical device MTF is not strongly affected by imperfections of the image projector and/or camera, such as distortion and astigmatism. The embodiments described herein allow for image quality separation between the optical device 100 and the measurement system 200, which may include defects attributable only to the camera or projector. The MTF is a metric that is used to determine the ability of the optical device 100 to convert contrast at a particular resolution from an object into an image.

Fig. 2 is a schematic cross-sectional view of a measurement system 200 according to embodiments described herein. The measurement system 200 includes a body 201 having a first opening 203 and a second opening 205 in the body 101 to allow a stage 207 to move therethrough. Stage 207 is operable to move in the X-direction, Y-direction, and Z-direction in body 201 of measurement system 200. The stage 207 includes a carrier 209 that is operable to hold the optical device 100 (as shown herein) or one or more substrates 101.

The measurement system 200 is operable to project an image such that the MTF of the optical device 100 can be determined. The stage 207 and the carrier 209 may be transparent such that the MTF achieved with the measurement system 200 is not affected by the translucency of the stage 207 or the carrier 209. The measurement system 200 is in communication with a controller 220 that is operable to control the operation of the measurement system 200 and method 300 described herein.

The controller 220 is coupled to the measurement system 200. The controller 220 includes a processor 252, a memory 254, and a support circuit 256 coupled to each other. The controller 220 is electrically coupled to the measurement system 200 via wires 258. The processor 252 may be one of any form of general purpose microprocessor, or general purpose Central Processing Unit (CPU), each of which may be used in an industrial setting, such as a Programmable Logic Controller (PLC), supervisory control and data acquisition (SCADA) system, a general purpose Graphics Processing Unit (GPU), or other suitable industrial controller. Memory 254 is non-transitory and may be one or more of readily available memory such as Random Access Memory (RAM), read Only Memory (ROM), or any other form of digital storage, whether local or remote. Memory 254 contains instructions that, when executed by processor 252, facilitate the execution of method 300. The instructions in memory 254 are in the form of a program product, such as a program that performs the methods of the present disclosure. The program code of the program product may conform to any of a number of different programming languages. Exemplary computer readable storage media include (but are not limited to): (i) A non-writable storage medium (e.g., a read-only memory device within a computer such as a CD-ROM disk readable by a CD-ROM drive, flash memory, ROM chip, or any type of solid state non-volatile semiconductor memory) on which information is permanently stored; and (ii) writable storage media (e.g., floppy disks within a diskette drive or hard-disk drive or any type of solid-state random-access semiconductor memory) on which alterable information is stored. Such computer-readable storage media, when carrying computer-readable instructions that direct the functions of the methods described herein, are examples of the present disclosure.

The measurement system 200 includes an upper portion 204 and a lower portion, the upper portion 204 being oriented toward a top side 222 of the optical device 100 and the lower portion being oriented toward a bottom side of the optical device 100. The upper portion 204 of the measurement system 200 includes an alignment camera 208, a light engine 210, and a reflection detector 212. The alignment camera 208 is operable to determine the position of the stage 207 and the optical device 100. The light engine 210 is operable to illuminate the first grating 104a. In some embodiments, which can be combined with other embodiments described herein, the light engine 210 projects an image of a pattern onto the first grating 104a. The reflection detector 212 detects the outcoupled light beam projected from the third grating 104c from the top side of the optical device 100. The lower portion 206 of the first subsystem 202 includes a code reader 214 and a transmission detector 216. The code reader 214 is operable to read codes of such optical devices, such as Quick Response (QR) codes or bar codes of the optical device 100. The code read by the code reader 214 may include instructions for retrieving the optical device MTFs of the various optical devices 100. The transmission detector 216 detects the outcoupled light beam projected from the third grating 104c through the bottom side of the optical device 100.

The method 300 described herein includes illuminating, by the light engine 210, the first grating 104a of the optical device 100, wherein the in-coupled light undergoes TIR until it is out-coupled (e.g., reflected or transmitted) as an image captured by the transmission detector 216. These images may correspond to red, green, and blue channels from light engine 210. These images are processed as described in method 300 to capture the MTF of optical device 100.

Fig. 3 is a flow chart of a method 300 for determining an optical device MTF. Fig. 4 is a schematic diagram of a measurement system 200 during a method of determining an optical device MTF. To facilitate explanation, the method 300 will be described with reference to the measurement system 200 shown in fig. 4. The method 300 is operable to be performed in other measurement systems not described herein.

The measurement system 200 includes a light engine 210 and a transmission detector 216. In some embodiments, which can be combined with other embodiments described herein, the measurement system 200 also includes a reflectance detector 212 (shown in fig. 2). The light engine 210 includes a light source 402, a reticle (reticle) 404, and a first lens 406. The light engine 210 may further include at least one of a quarter wave plate or a linear polarizer. In some embodiments, which may be combined with other embodiments described herein, the light source 402 is configured to project red, green, and blue light. Reticle 404 may be a display. The transmission detector 316 includes a second lens 408 and a camera 410.

In operation 301, a baseline image is projected by the light engine 210 of the measurement system 200 without the presence of the optical device 100. The baseline image is projected after the light source 402 projects red, green, or blue light through the reticle 404 to form a pattern. The baseline image has the pattern. In some embodiments, which can be combined with other embodiments described, the light engine 210 is a high resolution image projector having a field of view (FOV) of about 10 degrees to about 120 degrees. The FOV of the light engine 210 is fixed or adjustable. The pattern is determined by the reticle 404. Reticle 404 may have one of a checkerboard pattern, a pair of lines pattern, or a dot matrix pattern. In some embodiments, which can be combined with other embodiments described, the reticle 404 is a high resolution patterned mask. The pattern of reticle 404 may be formed via electron beam, ion beam, or photolithographic techniques. In other embodiments (which can be combined with the other embodiments described), the light engine 210 is one of an LCOS, CLP, micro LED, or OLED micro display.

In operation 302, the baseline image is captured. The baseline image may be captured by the transmission detector 216. The baseline image has a pattern formed by reticle 404. In some embodiments, which can be combined with other embodiments described herein, the transmission detector 216 includes a camera 410. Camera 410 is a high resolution camera. The camera 410 has a FOV of about 10 degrees to about 120 degrees. The FOV of camera 410 is fixed or adjustable. The camera 410 may be a CCD or CMOS sensor. The camera 410 has a FOV sampling rate of about 1 degree per measurement.

In operation 303, the baseline image is analyzed. In some embodiments, which can be combined with other embodiments described herein, the baseline image is analyzed to locate points on the baseline image. Each of the plurality of points may correspond to a different FOV across the baseline image. For example, each of the plurality of points may correspond to an edge of an adjacent square in the checkerboard pattern. The plurality of points are converted to a baseline function that depends on the pattern formed. For example, the baseline function may be a point spread function, a line spread function, or an edge spread function.

At operation 304, a baseline FFT or baseline MTF of the baseline function corresponding to the baseline image is obtained. To properly obtain the baseline FFT or baseline MTF, it is desirable to minimize the light intensity variation across the baseline image. The variation in light intensity across the baseline image can be reduced by adjusting the exposure time of the baseline image. The exposure time can be adjusted for each of the plurality of points of the baseline function.

In operation 305, as shown in FIG. 4, an image is projected by the light engine 210 of the measurement system 200 in the presence of the optical device 100. The image is projected after the light source 402 projects red, green, or blue light through the reticle 404 to form a pattern. The image includes the pattern. The pattern is projected onto the first grating 104a and undergoes TIR through the optical device 100 until the pattern is outcoupled from the third grating 104c. In some embodiments, which can be combined with other embodiments described herein, the optical device 100 can include a surface relief grating-based waveguide combiner, a volume hologram (volume hologram) -based waveguide combiner, a bird-bowl (bird-base) waveguide combiner, a partially-reflective mirror array combiner, or an optical-free combiner. The pattern is determined by the reticle 404. Reticle 404 may have one of a checkerboard pattern, a pair of lines pattern, or a dot matrix pattern. In some embodiments, which can be combined with other embodiments described, the reticle 404 is a high resolution patterned mask.

In operation 306, an image of the optical device 100 is captured. The image may be captured by the transmission detector 216. The image is outcoupled from the third grating 104c on the bottom side of the optical device 100 towards the transmission detector 216. The image has the pattern determined by the reticle 404. In some embodiments, which can be combined with other embodiments described herein, the transmission detector 216 includes a camera 410. In some embodiments, which can be combined with other embodiments described herein, the reflection detector 212 can capture an image of the pattern. For example, when the image is decoupled from the top side of the optical device 100, the reflection detector 212 may partially capture or fully capture the image.

In operation 307, the image is analyzed. In some embodiments, which can be combined with other embodiments described herein, the image is analyzed to locate a plurality of points. Each of the plurality of points may correspond to a different FOV across the image. For example, each of the plurality of points may correspond to an edge of an adjacent square in the checkerboard pattern. The plurality of points are converted into a function that depends on the pattern. For example, the function may be a point spread function, a line spread function, or an edge spread function. In some embodiments, which can be combined with other embodiments described herein, the function corresponds to the baseline function. For example, when the baseline function is a point spread function, the function will also be a point spread function.

In operation 308, a function FFT or a function MTF of the function is obtained corresponding to the image. In order to properly obtain the functional FFT or functional MTF, it is desirable to minimize the light intensity variation across the image. The variation in light intensity across the image can be reduced by adjusting the exposure time of the image. The exposure time may be adjusted for each of a plurality of points of the function.

In operation 309, the optical device MTF is obtained. The optics MTF is obtained by dividing the functional FFT corresponding to the image by the baseline FFT, or by dividing the functional MTF by the baseline MTF. The optical device MTF achieved by the method 300 is less susceptible to defects in the light engine 210. For example, astigmatism or distortion occurring in the light engine 210 is filtered out by taking a baseline FFT or a baseline MTF separately from a functional FFT or a functional MTF corresponding to the image to isolate and compensate for the occurring defects. In some embodiments, which can be combined with other embodiments described herein, the MTF of the complete FOV of the image capture optical device 100 of the optical device is used.

In summary, a method of determining an MTF of an optical device is described herein. The methods described herein include projecting a baseline image of a pattern from a light engine to a detector. The baseline image is analyzed to determine a baseline function. A baseline FFT or baseline MTF of the baseline function is taken. The method further includes projecting an image of the pattern from the light engine to one or more optical devices. The pattern is outcoupled from the one or more optical devices to the detector. The image is analyzed to determine a function. Corresponding to the image acquisition function FFT or function MTF. The optics MTF is determined by comparing the baseline FFT to the function FFT or by comparing the baseline MTF to the function MTF. The methods described herein will provide optical device MTF measurements without being affected by potential imperfections of the light engine. Additionally, the methods provided herein improve throughput for optical device fabrication and quality control by acquiring MTF data for a complete, dense FOV of an optical device with one image (e.g., processing all FOV angles in parallel in one shot) due to the high resolution image projector and high resolution camera each having a FOV of about 10 degrees to about 120 degrees. Overall, the methods provided herein allow for compensation of defects in image quality caused by image projectors and cameras by allowing isolation of the optics MTF. In this way, quality degradation can be avoided and higher throughput can be achieved.

While the foregoing is directed to embodiments of the present disclosure, other and further embodiments of the disclosure may be devised without departing from the basic scope thereof, and the scope thereof is determined by the claims that follow.

Claims

1. A method, comprising:

a baseline image of a projected pattern, the baseline image projected from a light engine of a measurement system, the measurement system having:

a stage disposed below the light engine, the stage operable to have one or more optical devices disposed thereon, wherein the light engine disposed above the stage projects the baseline image to the one or more optical devices; a kind of electronic device with high-pressure air-conditioning system

A detector oriented to face the stage;

capturing the baseline image, the baseline image captured by the detector;

analyzing the baseline image to locate a first plurality of points on the baseline image, the first plurality of points being converted to a baseline function;

acquiring a baseline Fast Fourier Transform (FFT) of the baseline function;

disposing the one or more optical devices on the stage;

projecting an image of the pattern, the image projected from the light engine to the one or more optical devices;

capturing the image, the image captured by the detector;

analyzing the image to locate a second plurality of points on the image, the second plurality of points being converted to a function;

obtaining a function FFT corresponding to the image; a kind of electronic device with high-pressure air-conditioning system

An optical device Modulation Transfer Function (MTF) of the one or more optical devices is determined, the optical device MTF determined by comparing the baseline FFT to the functional FFT corresponding to the image.

2. The method of claim 1, further comprising adjusting an exposure time of the baseline image when capturing the baseline image.

3. The method of claim 1, further comprising adjusting an exposure time of the image while capturing the image.

4. The method of claim 1, wherein the baseline function and the function are one of a point spread function, a line spread function, or an edge spread function.

5. The method of claim 1, wherein determining the optical device MTF comprises dividing the functional FFT corresponding to the image by the baseline FFT.

6. The method of claim 1, further comprising capturing the image by a reflective detector oriented to face the stage.

7. The method of claim 1, wherein the light engine is a high resolution image projector having a field of view (FOV) of about 10 degrees to about 120 degrees.

8. The method of claim 1, wherein one or more of each of the first plurality of points and each of the second plurality of points represent edges of adjacent quadrilaterals in a checkerboard pattern.

9. A method, comprising:

A detector oriented to face the stage;

capturing the baseline image, the baseline image captured by the detector;

acquiring a baseline Fast Fourier Transform (FFT) corresponding to the baseline image;

projecting an image of the pattern to the one or more optical devices, the image being projected from the light engine to the one or more optical devices;

capturing the image, the image captured by the detector;

10. The method of claim 9, further comprising adjusting an exposure time of the baseline image when capturing the baseline image.

11. The method of claim 9, wherein the light engine is a high resolution image projector having a field of view (FOV) of about 10 degrees to about 120 degrees.

12. The method of claim 9, wherein one or more of each of the first plurality of points and each of the second plurality of points represent edges of adjacent quadrilaterals in a checkerboard pattern.

13. The method of claim 9, further comprising capturing the image by a reflectance detector,

the reflective detector is oriented to face the stage.

14. The method of claim 9, wherein determining the optical device MTF of the one or more optical devices comprises dividing the functional FFT corresponding to the image by the baseline FFT.

15. A method, comprising:

projecting a baseline image of the pattern from the light engine to a detector of the measurement system;

capturing the baseline image by the detector;

analyzing the baseline image;

projecting an image of the pattern from the light engine to one or more optical devices through which the image is projected to the detector;

capturing the image by the detector;

analyzing the image; a kind of electronic device with high-pressure air-conditioning system

An optical device Modulation Transfer Function (MTF) of the one or more optical devices is determined.

16. The method of claim 15, wherein analyzing the baseline imagery includes determining a baseline MTF, analyzing the imagery includes determining a functional MTF, and determining the optical device MTF of the one or more optical devices includes dividing the functional MTF determined by analyzing the imagery by the baseline MTF.

17. The method of claim 15, wherein analyzing the baseline image comprises determining a baseline Fast Fourier Transform (FFT), analyzing the image comprises determining a functional FFT corresponding to the image, and determining the optical device MTF of the one or more optical devices comprises dividing the functional FFT determined by analyzing the image by the baseline FFT.

18. The method of claim 15, further comprising adjusting an exposure time of the baseline image when capturing the baseline image.

19. The method of claim 15, wherein the light engine is a high resolution image projector having a field of view (FOV) of about 10 degrees to about 120 degrees.

20. The method of claim 15, further comprising a stage disposed below the light engine and capturing the image by a reflective detector oriented to face the stage.