Edge inspection system for inspection of optical devices

Abstract

The embodiments described herein relate to an inspection system for illumination optics. The inspection system includes a step, a focusing lens, a light source, a reflective surface, and a camera. The inspection system is operable to provide light to a substrate. The substrate is positioned on the inspection system such that its edges are exposed. The inspection system focuses light onto the edges, allowing the light to propagate through the substrate. The light is coupled out from the substrate, illuminating one or more optical devices disposed on the substrate. This illumination allows the camera to capture an image to be inspected. The image is inspected to check for defects in the substrate.

Description

Technical Field

[0001] The embodiments of this disclosure generally relate to optical elements. More specifically, the embodiments of this disclosure relate to inspection systems and methods for inspecting optical devices. Prior Technology

[0002] Optical devices, including waveguide combiners (such as augmented reality waveguide combiners) and planar optical devices (such as metasurfaces), are used to aid in image overlay. The generated light propagates through the optical device until it exits and coats the surrounding environment. Identifying defects in the optical device improves the overall performance of the manufactured optical device. However, inspecting for defects in optical devices can be challenging and time-consuming. For example, structures may be present in or on the optical device, and due to the subwavelength dimensions of these structures, it may be difficult to inspect the optical device from above.

[0003] It is advantageous to inspect optical devices with high throughput to ensure they are free of defects. Inspection processes that can be integrated into the manufacturing methods of optical devices are also beneficial. Directing light onto optical devices can improve the visibility of structures mounted thereon; however, effectively directing light onto optical devices with sufficient contrast to inspect structures is difficult. Therefore, there is a need in the art for an improved inspection system. Summary of the Invention

[0004] In one embodiment, an inspection system is provided. The inspection system includes a step. The step includes an inner support operable to hold a substrate on which one or more optical devices are disposed. The step further includes an outer support and a bottom support. The inspection system further includes a cover disposed on the outer support. The inner support, outer support, bottom support, and cover define an inner region. The inner support and cover define a slit. The inspection system further includes a light source operable to emit light. The light source is disposed in the inner region. The inspection system further includes a focusing lens operable to focus light onto the slit. The focusing lens is optically coupled to the light source in the inner region.

[0005] In another embodiment, an inspection method is provided. The method includes the steps of: directing light from a light source onto a substrate on an internal support of an inspection system step. The substrate is positioned such that its edge is aligned with a slit in the inspection system, the slit being defined by the internal support and a cover disposed on an external support of the step. A light source is disposed in an internal region of the step and directs light through the slit to the edge of the substrate to illuminate one or more optical devices disposed in or on the substrate. The method further includes the steps of: capturing images of the one or more optical devices and defect inspection images of the one or more optical devices.

[0006] In yet another embodiment, an inspection method is provided. The method includes the steps of: forming a cutting path along the periphery of one or more optical devices disposed in or on a substrate, and guiding light from a light source to the substrate on an internal support of a step in an inspection system. The substrate is positioned such that its edge is aligned with a slit in the inspection system, the slit being defined by an internal support and a cover disposed on an external support of the step. A light source is disposed in an internal region of the step and guides light through the slit to the edge of the substrate to illuminate the one or more optical devices disposed in or on the substrate. The method further includes the steps of: capturing images of the one or more optical devices and inspecting the images for defects along the cutting path formed around the periphery of the one or more optical devices. Simple Explanation of the Diagram

[0007] The features of this disclosure have been briefly summarized above and discussed in more detail below, which can be understood by referring to the embodiments illustrated in the accompanying drawings. However, it should be noted that the drawings only illustrate exemplary embodiments and should not be considered as limiting the scope, as other equally effective embodiments are permissible in this disclosure.

[0008] Figure 1A is a schematic perspective view of an inspection system according to an embodiment.

[0009] Figure 1B is a schematic cross-sectional view of a first configuration of the inspection system according to an embodiment.

[0010] Figure 1C is a schematic cross-sectional view of a first configuration of the inspection system according to an embodiment.

[0011] Figure 1D is a schematic cross-sectional view of a second configuration of the inspection system according to an embodiment.

[0012] Figure 1E is a schematic cross-sectional view of a second configuration of the inspection system according to an embodiment.

[0013] Figure 2 is a schematic top view of the substrate according to an embodiment.

[0014] Figure 3 is a flowchart of a method for inspecting an optical device according to an embodiment.

[0015] For ease of understanding, the same reference numerals are used where possible to denote common elements in the figures. It is contemplated that elements and features in one embodiment may be advantageously used in other embodiments without further description. Implementation

[0016] The embodiments disclosed herein relate to an inspection system and method for inspecting optical devices. The inspection system includes a step. The step includes an internal support operable to hold a substrate on which one or more optical devices are disposed. The step further includes an external support and a bottom support. The inspection system further includes a cover disposed on the external support. The internal support, external support, bottom support, and cover define an internal region. The internal support and cover define a slit. The inspection system further includes a light source operable to emit light. The light source is disposed in the internal region. The inspection system further includes a focusing lens operable to focus light onto the slit. The focusing lens is optically coupled to the light source in the internal region.

[0017] In one embodiment that can be combined with other embodiments described herein, the method includes the step of: positioning a substrate on an internal support of an inspection system's step. The substrate is positioned such that the edge of the substrate is aligned with a slit in the inspection system. The slit is defined by the internal support and a cover disposed on an external support of the step. The method further includes the step of: guiding light from a light source disposed in an internal region of the step through the slit to the edge of the substrate to illuminate one or more optical devices disposed in or on the substrate. The method further includes the step of: capturing an image of the one or more optical devices. The method further includes the step of: inspecting the image for defects in the one or more optical devices. In another embodiment that can be combined with other embodiments described herein, the method includes the step of: forming a cutting path along the periphery of one or more optical devices disposed in or on the substrate. The method further includes the step of: positioning the substrate on an internal support of an inspection system's step. The substrate is positioned such that the edge of the substrate is aligned with a slit in the inspection system. The slit is defined by the internal support and a cover disposed on an external support of the step. The method further includes the step of: guiding light from a light source disposed in an internal region of the step through the slit to the edge of the substrate to illuminate one or more optical devices. The method further includes the step of: acquiring images of one or more optical devices. The method further includes the step of: inspecting the images for defects along cutting paths provided around the periphery of the one or more optical devices.

[0018] Figure 1A is a schematic perspective view of the inspection system 100. The inspection system 100 includes a first configuration 101A as shown in Figures 1B and 1C. The inspection system 100 includes a second configuration 101B as shown in Figures 1D and 1E. The inspection system 100 is configured to hold a substrate 102. The inspection system 100 is operable to direct light to the substrate 102. Specifically, the inspection system 100 is operable to direct light to an edge 105 of the substrate 102. The light propagates through the substrate 102 via total internal reflection (TIR). The light is coupled out of the substrate 102 through one or more optical devices (as shown in Figure 2) disposed on the substrate 102. The light illuminates the substrate 102 such that the one or more optical devices (as shown in Figure 2) are visible to a camera 112 disposed above the inspection system 100. Therefore, the inspection system is operable for inspecting and identifying defects in the substrate 102 and the one or more optical devices (as shown in Figure 2).

[0019] The inspection system 100 can be positioned in an in-line inspection station. Therefore, one or more substrates 102 can be inspected individually. For example, one or more substrates 102 can be inspected at multiple stages of the manufacturing process. During the manufacturing process, the inspection system 100 can be installed on the manufacturing equipment used.

[0020] Figure 1B is a schematic cross-sectional view of the first configuration 101A of the inspection system 100. Figure 1D is a schematic cross-sectional view of the second configuration 101B of the inspection system 100. As shown in Figures 1A and 1B, the first configuration 101A of the inspection system 100 includes a step 104, a cover 130, a focusing lens 106, a light source 108, a reflective surface 110, and a camera 112. As shown in Figures 1A and 1D, the second configuration of the inspection system 100 includes a step 104, a cover 130, a focusing lens 106, a light source 108, and a camera 112.

[0021] Step 104 has an inner support 114, a bottom support 126, and an outer support 128. A cover 130 is disposed above the step 104. The cover 130 is coupled to the outer support 128. The cover 130, inner support 114, bottom support 126, and outer support 128 define an internal region 120 of the inspection system 100. The cover 130 includes a cover surface 109. The cover surface 109 is angled relative to the bottom support 126. The cover surface 109 is angled inward toward the interior of the inspection system 100. For example, the cover surface 109 is angled toward a substrate 102 held in the inspection system 100.

[0022] A focusing lens 106, a light source 108, and a reflective surface 110 are disposed in an internal region 120. An internal support 114 is operable to support a substrate 102. The substrate 102 is seated on the internal support 114 such that the internal support 114 does not contact one or more optical devices (as shown in FIG. 2). The internal support 114 includes a horizontal surface to support the substrate 102. In one embodiment that can be combined with other embodiments described herein, a cover 130 is opaque, resulting in a high contrast between the substrate 102 and the cover 130 when illuminated. The cover 130 comprises an opaque material. The opaque material includes, but is not limited to, aluminum-containing materials. The aluminum-containing material may be anodized aluminum or aluminum impregnated with carbon-filled polyether ether ketone (PEEK). Furthermore, the cover 130 may be coated with a light-absorbing material to produce a high contrast between the substrate 102 and the cover 130 when illuminated. For example, a light-absorbing material is formed using an anodizing process. The step 104 can be configured to hold any substrate 102. The step 104 can be configured to correspond to any contour of the substrate 102. Although the step 104 shown in Figures 1A-1E is configured to hold a circular substrate, the inspection system 100 is not limited to the shape or size of the substrate 102. For example, the inspection system 100 can be configured to hold a rectangular substrate.

[0023] A camera 112 is positioned above a substrate 102. When illuminated by the inspection system 100, the camera 112 is operable to capture an image of the substrate 102 and one or more optical devices (as shown in FIG. 2). Light is guided through the substrate 102 and coupled out from the substrate 102 to create high contrast between the material of the substrate 102 and the one or more optical devices (as shown in FIG. 2), making the one or more optical devices (as shown in FIG. 2) visible in the image. The image can be inspected to identify defects in the substrate 102. The illumination system is used to inspect the substrate 102 to check for at least one of the following: fall-on particles, missing patterns, discoloration, or film inhomogeneity.

[0024] Furthermore, the cutting path (as shown in Figure 2) along the periphery of one or more optical devices defines the location where a laser ablation or filamentation process occurs before the optical devices are removed from the substrate 102. The cutting path can be inspected using the inspection system 100 to determine its quality and ensure that there are no stress cracks or defects along the cutting path.

[0025] Figure 1C is a schematic cross-sectional view 103A of a first configuration 101A of the inspection system 100. A light source 108 is disposed in an inner region 120 of the step 104. The light source 108 is coupled to an external support 128 within the inner region 120. The light source 108 is powered via an external power connection formed through the external support 128. For example, the external support includes a bumped-out connector to provide power. The light source 108 is operable to emit light. The light source 108 can emit TIR-suitable light in the substrate 102. The light source 108 includes at least one of one or more light-emitting diodes or one or more ultraviolet light sources. The one or more light-emitting diodes can be one or more of red, green, blue, or white light-emitting diodes. In one embodiment that can be combined with other embodiments described herein, the light source 108 includes a resilient printed circuit board disposed along the external support 128 of the step 104. Therefore, light will be uniformly distributed onto the substrate 102. The light-emitting diodes are disposed above the printed circuit board such that light is directed toward the substrate 102. A light source 108 is vertically disposed in the inner region 120. The light source 108 is parallel to the edge 105 of the substrate 102. In one example, the light source 108 completely surrounds the step 104. In another embodiment, which can be combined with other embodiments described herein, one or more light sources 108 are disposed along the outer support 128 such that the one or more light sources 108 can guide light to the portion of the substrate 102 corresponding to the one or more light sources 108.

[0026] A focusing lens 106 is operable to receive light emitted from a light source 108. The focusing lens 106 directs light to the edge 105 of a substrate 102. The focusing lens 106 includes, but is not limited to, plastic, quartz, glass, or combinations thereof. The plastic may be polycarbonate. The substrate 102 is disposed on an inner support 114. The focusing lens 106 may be engaged with a cover 130, an outer support 128, and / or a bottom support 126. The focusing lens 106 is configured along an inner region 120 of a step 104. Light travels through the focusing lens 106 in the inner region 120 to the substrate 102. The focusing lens 106 includes a lens surface 107 in a first configuration 101a. The lens surface 107 faces the inner region 120. The lens surface 107 is angled relative to the bottom support 126. The angle between the lens surface 107 and the bottom support 126 is from about 5° to about 85°, about 10° to about 80°, about 15° to about 80°, about 20° to about 75°, about 25° to about 70°, about 30° to about 65°, about 35° to about 60°, about 40° to about 55°, or about 45° to about 60°.

[0027] The focusing lens 160 is an optical fiber material configured to concentrate light onto the slit 116. The focusing lens 160 may have a square or rectangular cross-section. For example, the focusing lens 106 guides light through the slit 116. The slit 116 is defined as the distance that light emitted from the light source 108 can escape from the internal region 120. The slit 116 is further defined as the distance between the internal support 114 and the cover plate 130. The edge 105 of the substrate 102 is disposed on the internal support 114 such that the focusing lens 106 guides light through the slit 116 to the edge 105. The slit 116 is between approximately 0.1 mm and approximately 2 mm. The slit 116 corresponds to the thickness 124 of the substrate 102, such that the edge 105 is exposed to the maximum amount of light from the light source 108. The thickness 124 is between approximately 0.1 mm and approximately 2 mm. The exit thickness 111 of the focusing lens 106 is substantially equal to the thickness 124 of the substrate 102 and the slit 116, corresponding to the thickness of the portion of the focusing lens adjacent to the slit 116.

[0028] A reflective surface 110 is disposed between the inner support 114 and the bottom support 126. In one example, the reflective surface 110 is coupled to the inner support 114 and the bottom support 126. In one embodiment, which may be combined with other embodiments described herein, the reflective surface 110 is a film, sheet, or foil of reflective material coupled to the focusing lens 106. In another example, the reflective surface 110 is a reflective strip, foil material, or polished metal material. The reflective surfaces 110 are arranged in a line on the outer surface of the focusing lens 106. The reflective surfaces 110 may be arranged at an angle relative to the bottom support 126. For example, the angle of the reflective surface 110 relative to the bottom support 126 ranges from about 5° to about 85°, about 10° to about 80°, about 15° to about 80°, about 20° to about 75°, about 25° to about 70°, about 30° to about 65°, about 35° to about 60°, about 40° to about 55°, or about 45° to about 60°. The reflective surface 110 helps to guide light from the light source 108 to the edge 105 of the substrate 102. In one embodiment that can be combined with other embodiments described herein, the reflective surface 110 may be disposed on the inner region 120 of the step 104. In one embodiment that can be combined with other embodiments described herein, when the light source 108 includes one or more ultraviolet light sources, the reflective surface 110 will reflect ultraviolet light. The reflective surface 110 and the focusing lens 106 guide light to the substrate 102 with increased efficiency because all or most of the light is directed to the edge 105.

[0029] Figure 1E is a schematic cross-sectional view 103B of a second configuration 101B of the inspection system 100 shown in Figure 1D. A light source 108 is disposed in the inner region 120 of the step 104. The light source 108 is coupled to an outer support 128, a bottom support 126, and an inner support 114. The light source 108 is operable to emit light. The light source 108 can emit TIR-suitable light within the substrate 102. The light source 108 includes at least one of one or more light-emitting diodes or one or more ultraviolet light sources. The one or more light-emitting diodes can be one or more of red, green, blue, or white light-emitting diodes. In one embodiment that can be combined with other embodiments described herein, the light source 108 includes a rigid printed circuit board configured such that the printed circuit board is disposed along the inner region 120 of the step 104. The light-emitting diodes are disposed above the printed circuit board such that light is directed toward a cover 130 and a focusing lens 106. Thus, light is uniformly distributed onto the substrate 102. In one example, the light source 108 completely surrounds the step 104. In another embodiment that can be combined with other embodiments described herein, one or more light sources 108 are disposed along the inner region 120 such that the one or more light sources 108 can guide light to a portion of the substrate 102 corresponding to the one or more light sources 108.

[0030] A focusing lens 106 is operable to receive light emitted from a light source 108. The focusing lens 106 is disposed above the top surface 113 of the light source 108. The light source 108 emits light toward the focusing lens 106 in a vertical direction. In some embodiments, the focusing lens 106 is horizontally positioned on the top surface 113 of the light source 108. The focusing lens 106 is circularly disposed along the entire internal region 120 according to a step 104. The focusing lens 106 guides light to the edge 105 of the substrate 102. The focusing lens 106 includes, but is not limited to, plastic, quartz, glass, or combinations thereof. The plastic may be polycarbonate. The substrate 102 is disposed on an internal support 114. The focusing lens 106 may be joined to a cover 130, an external support 128, the light source 108, and / or the internal support 114. In one embodiment, the cover 130, inner support 114, bottom support 126, and outer support 128 are machined such that light from the light source 108 is tunneled through the focusing lens 106 to the substrate 102. The focusing lens 106 is configured along the inner region 120 of the step 104.

[0031] The focusing lens 160 is an optical fiber material configured to concentrate light onto the slit 116. The focusing lens 160 may have a square or rectangular cross-section. Light travels through the focusing lens 106 in the inner region 120 to the substrate 102. The focusing lens 106 guides the light through the slit 116. The slit 116 is defined as the distance that light emitted from the light source 108 can escape from the inner region 120. The slit 116 is defined as the distance between the inner support 114 and the cover 130. The edge 105 of the substrate 102 is disposed on the inner support 114 such that the focusing lens 106 guides light through the slit 116 to the edge 105. The slit 116 is between approximately 0.1 mm and approximately 2 mm. The slit 116 corresponds to the thickness 124 of the substrate 102, such that the edge 105 is exposed to the maximum amount of light from the light source 108. The thickness 124 is between approximately 0.1 mm and approximately 2 mm. The exit thickness 111 of the focusing lens 106 is substantially equal to the thickness 124 of the substrate 102 and the slit 116, corresponding to the thickness of the portion of the focusing lens adjacent to the slit 116.

[0032] Figure 2 is a schematic top view of substrate 102. Substrate 102 is operable to be held in inspection system 100. Substrate 102 is operable to be illuminated by inspection system 100. Substrate 102 includes one or more optical devices 202. The one or more optical devices 202 include optical device structures 206. In one embodiment that can be combined with other embodiments described herein, a region of optical device structure 206 corresponds to one or more gratings 204. One or more optical devices 202 are fabricated on substrate 102. One or more optical devices 202 may be disposed in or on substrate 102. Substrate 102 may include, but is not limited to, silicon (Si), silicon nitride (SiN), silicon dioxide (SiO2), fused silica, quartz, silicon carbide (SiC), germanium (Ge), silicon germanium (SiGe), indium phosphide (InP), gallium arsenide (GaAs), gallium nitride (GaN), sapphire, or combinations thereof. In one embodiment that can be combined with other embodiments described herein, one or more optical devices 202 are planar optical devices, such as metasurfaces. In another embodiment that can be combined with other embodiments described herein, one or more optical devices 202 are waveguide combiners, such as augmented reality waveguide combiners.

[0033] The substrate 102 can be any substrate used in the art, and can be opaque or transparent depending on the intended use of the substrate. Furthermore, the substrate selection can further include different shapes, thicknesses, and diameters of the substrate 102. For example, the substrate 102 can be a single-crystal wafer of any size, such as having a radius from about 150 mm to about 450 mm. The substrate 102 can have any number of one or more optical devices 202 disposed thereon, and is not limited to the number of one or more optical devices 202 shown in FIG. 2. The substrate 102 is positioned in the inspection system 100 such that the one or more optical devices 202 are illuminated and have high contrast with the material of the substrate 102.

[0034] Figure 3 is a flowchart of a method 300 for inspecting an optical device. For ease of explanation, method 300 will be described with reference to the inspection system 100 of Figures 1A-1E. A first configuration 101A and a second configuration 101B of the inspection system 100 are operable for use with the method 300 described herein. However, it should be noted that inspection systems other than inspection system 100 may be used in conjunction with method 300.

[0035] In operation 301, substrate 102 is positioned. Substrate 102 can be positioned on the internal support 114 of inspection system 100. Substrate 102 is positioned such that the edge 105 of substrate 102 is exposed. In one embodiment that can be combined with other embodiments described herein, substrate 102 is manually placed on internal support 114. In another embodiment that can be combined with other embodiments described herein, substrate 102 is placed on internal support 114 by a transfer robot. In yet another embodiment that can be combined with other embodiments described herein, one or more optical devices 202 disposed on substrate 102 can be cut along a cutting path along the periphery of one or more optical devices 202 prior to operation 301. For example, a laser ablation process or a melting process can be performed to form the cutting path when positioning substrate 102 or prior to operation 301.

[0036] In operation 302, light is guided to the edge 105 of substrate 102. Light can be guided from light source 108. Light source 108 can guide light through focusing lens 106 to edge 105. Focusing lens 106 directs light from light source 108 to slit 116. In a first configuration, light source 108 is coupled to the outer support 128 of step 104 such that light source 108 is parallel to the edge 105 of substrate 102. Focusing lens 106 is optically coupled to light source 108 and extends through inner region 120 of step 104 to slit 116. In a second configuration, light source 108 is coupled to outer support 128, bottom support 126, and inner support 114. Focusing lens 106 is coupled to top surface 113 of light source 108. Focusing lens 106 is positioned in line with slit 116. In both the first and second configurations, the exit thickness 111 of the focusing lens 106 (corresponding to the thickness of the adjacent slit 116 of the focusing lens) is substantially equal to the thickness 124 of the substrate 102. The slit 116 corresponds to the thickness 124 of the substrate 102, such that light is directed to the edge 105 rather than to the outside of the inspection system 100. In the first configuration 101A, a reflective surface 110 is disposed on the focusing lens 106 to increase the amount of light directed to the edge 105 during operation 302.

[0037] The positioning of the light source 108 and the focusing lens 106 allows light to travel from the light source 108 to the edge 105 of the substrate 102, ensuring that as much light as possible is directed to the edge 105 given the limited amount of light escaping from the inspection system 100. This improves both the efficiency and quality of the inspection process. Furthermore, due to its compact design and simple structure, this inspection system benefits from improved manufacturability compared to other inspection systems.

[0038] The light contacts the edge 105 of the substrate 102 and propagates through the substrate 102 via total internal reflection. The light is coupled out of the substrate 102 by one or more optical devices 202 disposed on the substrate 102. The light coupled out from the substrate 102 forms a high contrast with the materials of the substrate 102 and the step 104, so as to illuminate one or more optical devices 202.

[0039] In operation 303, an image of substrate 102 is captured. This image is captured by camera 112, which is positioned above substrate 102. In operation 304, the image is inspected. The image is inspected for defects on substrate 102. Inspection system 100 is used to inspect substrate 102 to check for at least one of the following: detached particles, missing patterns, discoloration, or film inhomogeneity. In embodiments where one or more optical devices 202 are cut along a cutting path prior to operation 301, the cutting path can be inspected to determine its integrity. For example, the cutting path can be inspected for stress cracks.

[0040] In summary, this application provides an inspection system for illumination optics. The inspection system includes a step, a focusing lens, a light source, a reflective surface, and a camera. The inspection system is operable to provide light to a substrate. The substrate is positioned on the inspection system such that its edges are exposed. The inspection system focuses light onto the edges, allowing the light to propagate through the substrate. The light is coupled out from the substrate, illuminating one or more optical devices disposed on the substrate. This illumination allows the camera to capture an image to be inspected. The image is inspected to check for defects in the substrate. The substrate can be inspected at multiple stages of the manufacturing process, and each substrate can be inspected individually. The inspection system can be installed on manufacturing equipment used during the manufacturing process, thus providing high-volume inspection of substrates.

[0041] Although the foregoing description is directed to embodiments of this disclosure, other and further embodiments of this disclosure may be designed without departing from the essential scope of this disclosure, and the scope of this disclosure is defined by the following patent application scope.

[0042] 100: Inspection System 101A: First Configuration 101B: Second Configuration 102:Substrate 103A: Section 103B: Section 104: Steps 105: Edge 106: Focusing lens 107: Lens surface 108: Light Source 109: Cover surface 110: Reflective surface 111: Export Thickness 112: Camera 113: Top surface 114: Internal support components 116: Slit 120: Internal Area 124: Thickness 126: Bottom support component 128: External support components 130: Cover piece 160: Focusing lens 202: Optical Devices 204: Raster 206: Structure of Optical Device 300: Method 301: Operation 302: Operation 303: Operation 304: Operation

[0043] Domestic storage information (please note in order of storage institution, date, and number) none Overseas storage information (please note in the order of storage country, institution, date, and number) none

Claims

1. An inspection system, comprising: A stage comprising: an inner support operable to hold a substrate on which one or more optical devices are disposed; an outer support; and a bottom support; a cover disposed on the outer support, wherein the inner support, the outer support, the bottom support, and the cover define an inner region, wherein the inner support and the cover define a slit; a light source operable to emit light disposed in the inner region; and a focusing lens operable to focus the light onto the slit, the focusing lens being optically coupled to the light source in the inner region.

2. The inspection system as described in claim 1, wherein: The light source is coupled to the external support in the internal region; The focusing lens extends between the light source and the slit; and a reflective surface disposed between the inner support and the bottom support, the reflective surface being operable to guide light from the light source to the slit.

3. The inspection system as described in claim 2, wherein the reflective surface is coupled to the focusing lens.

4. The inspection system as described in claim 3, wherein the reflective surface is a film, sheet, or foil of reflective material.

5. The inspection system as described in claim 1, wherein: The light source is coupled to the external support, the bottom support, and the internal support of the internal region; The focusing lens is disposed between a top surface of the light source and the cover.

6. The inspection system as claimed in claim 1, wherein an exit thickness corresponding to a portion of the focusing lens adjacent to the slit is substantially equal to the slit itself.

7. The inspection system as described in claim 1, wherein the slit is between about 0.1 mm and about 2 mm.

8. An inspection method comprising the steps of: directing light from a light source to a substrate on an inner support of a step in an inspection system, the substrate being positioned such that an edge of the substrate is aligned with a slit in the inspection system, the slit being defined by the inner support and a cover being disposed on an outer support of the step, wherein the light source is disposed in an inner region of the step and directs the light through the slit to the edge of the substrate to illuminate one or more optical devices disposed in or on the substrate; capturing images of the one or more optical devices; and inspecting the images for defects in the one or more optical devices.

9. The method as described in claim 8, wherein the interior region is defined by the interior support, the exterior support, the cover and a bottom support, the bottom support being disposed below the interior support and the exterior support.

10. The method as described in claim 8, wherein the image is captured using a camera disposed above the substrate.

11. The method as described in claim 8, wherein a reflective surface disposed between the inner support and a bottom support of the step guides the light through the slit.

12. The method as described in claim 8, wherein the slit corresponds to a thickness of the substrate such that the light contacts the edge of the substrate.

13. The method as described in claim 8, wherein the step of irradiating the substrate with light includes the step of coupling the light out of the substrate through one or more optical devices disposed on the substrate.

14. The method as described in claim 8, wherein the light is propagated to the slit through a focusing lens coupled to the light source in the interior region.

15. An inspection method comprising the steps of: forming a cutting path along a periphery of one or more optical devices disposed in or on a substrate; directing light from a light source to a substrate on an inner support of a step in an inspection system, the substrate being positioned such that an edge of the substrate is aligned with a slit in the inspection system, the slit being defined by the inner support and a cover being disposed on an outer support of the step, wherein the light source is disposed in an inner region of the step and directs the light through the slit to the edge of the substrate to illuminate one or more optical devices disposed in or on the substrate; capturing images of the one or more optical devices; and inspecting the images for defects along the cutting path disposed around the periphery of the one or more optical devices.

16. The method as described in claim 15, wherein the step of irradiating the substrate with light includes the step of coupling the light out of the substrate through one or more optical devices disposed on the substrate.

17. The method as described in claim 15, wherein the interior region is defined by the interior support, the exterior support, the cover and a bottom support, the bottom support being disposed below the interior support and the exterior support.

18. The method as described in claim 15, wherein a reflective surface disposed between the inner support and a bottom support guides the light through the slit.

19. The method as described in claim 15, wherein the slit corresponds to a thickness of the substrate such that the light contacts the edge of the substrate.

20. The method as described in claim 15, wherein the step of inspecting the cutting paths for defects includes the following steps: inspecting for stress cracks along the cutting paths.

Images