Waveguides with integrated optical elements and methods of making the same

Abstract

To provide favorable waveguides with integrated optical elements and methods of making the same.SOLUTION: An example waveguide can include a polymer layer having a substantially optically transparent material with first and second major surfaces configured such that light containing image information can propagate through the polymer layer and be guided therein by reflecting from the first and second major surfaces via total internal reflection. The first surface can include first smaller and second larger surface portions monolithically integrated with the polymer layer and with each other. The first smaller surface portion can include at least a part of an in-coupling optical element configured to couple light incident on the in-coupling optical element into the polymer layer for propagation therethrough by reflection from the second major surface and the second larger surface portion of the first major surface.SELECTED DRAWING: Figure 10

Description

[Technical field]

[0001] (Priority Claim) This application claims the benefit of priority under 35 U.S.C. 119(e) to U.S. Provisional Application No. 62 / 651,553, filed April 2, 2018, the entire disclosure of which is expressly incorporated herein by reference. (CROSS REFERENCE TO RELATED APPLICATIONS)

[0002] This application is related to the following patent applications: U.S. Application No. 14 / 555,585, filed November 27, 2014, and published July 23, 2015 as U.S. Publication No. 2015 / 0205126; U.S. Application No. 14 / 690,401, filed April 18, 2015, and published October 22, 2015 as U.S. Publication No. 2015 / 0302652; The present disclosure also incorporates by reference in its entirety U.S. Application No. 14 / 212,961, filed March 14, 2014 (now U.S. Patent No. 9,417,452, issued August 16, 2016), and U.S. Application No. 14 / 331,218, filed July 14, 2014, and published October 29, 2015 as U.S. Publication No. 2015 / 0309263.

[0003] The present disclosure relates to display systems, and more particularly to augmented reality display systems. [Background technology]

[0004] Modern computing and display technologies have facilitated the development of systems for so-called "virtual reality" or "augmented reality" experiences, in which digitally reproduced images or portions thereof are presented to a user in a manner that appears or may be perceived as real. Virtual reality, or "VR", scenarios typically involve the presentation of digital or virtual image information without transparency to other actual real-world visual inputs, and augmented reality, or "AR", scenarios typically involve the presentation of digital or virtual image information as an extension to the visualization of the real world around the user. Mixed reality, or "MR", scenarios are a type of AR scenario that typically involve virtual objects that are integrated into and respond to the natural world. For example, in MR scenarios, AR image content is perceived as being occluded by or otherwise interacting with objects in the real world.

[0005] 1, an augmented reality scene 10 is depicted in which a user of the AR technology sees a real-world park-like setting 20 featuring people, trees, buildings in the background, and a concrete platform 30. In addition to these items, the user of the AR technology also perceives that they "see" "virtual content," such as a robotic figure 40 standing on the real-world platform 30 and a flying cartoon-like avatar character 50 that appears to be an anthropomorphic bumblebee, although these elements 40, 50 do not exist in the real world. Because of the complexity of the human visual perception system, it is difficult to produce AR technology that facilitates a comfortable, natural-feeling, and rich presentation of virtual image elements among other virtual or real-world image elements.

[0006] The systems and methods disclosed herein address various challenges associated with AR or VR technology. Summary of the Invention [Means for solving the problem]

[0007] This disclosure provides various embodiments of waveguides, systems, and methods, each having several innovative aspects, no one of which is solely responsible for the desirable attributes disclosed herein. 1. A waveguide comprising: A polymer layer comprising a substantially optically transparent material having first and second major surfaces configured such that light containing image information may propagate through and be guided within the polymer layer by reflecting off the first and second major surfaces via total internal reflection. Equipped with the first surface includes a first smaller surface portion and a second larger surface portion monolithically integrated with the polymer layer and with each other; the first smaller surface portion comprises at least a portion of an internal coupling optical element configured to couple light incident on the internal coupling optical element into the polymer layer for propagation through the polymer layer by reflection from the second major surface and a second, larger surface portion of the first major surface. 2. The waveguide of example 1, wherein the internal coupling optical element comprises a turning mirror configured to deflect light containing image information within the waveguide. 3. The waveguide of example 2, wherein the turning mirror comprises a second, larger surface portion of the first major surface and a first, smaller surface portion of the first major surface that is tilted relative to the second major surface. 4. The waveguide of claim 2 or 3, wherein the turning mirror has optical power. 5. The waveguide of example 4, wherein the optically powered turning mirror comprises a second, larger surface portion of the first major surface and a first, smaller surface portion of the first major surface that is curved relative to the second major surface. 6. The waveguide of any of Examples 2-5, wherein the turning mirror further comprises a metallization disposed on a first smaller surface portion of the first major surface. 7. The waveguide of example 1, wherein the internal coupling optical element comprises a lens. 8. The waveguide of example 7, wherein the lens comprises a second, larger surface portion of the first major surface and a first, smaller surface portion of the first major surface that is curved relative to the second major surface. 9. The waveguide of example 1, wherein the internal coupling optical element comprises a grating. 10. The waveguide of example 9, wherein the grating comprises a first smaller surface portion of the first major surface having an undulating surface relief. 11. The waveguide of any of Examples 1-10, wherein the polymer layer, including at least a portion of the internal coupling optical element, comprises molded optics. 12. The waveguide of any of Examples 1-11, wherein the plurality of surfaces have a surface roughness of about 0.1 nm to about 2.0 nm. 13. A waveguide comprising: A molded optical system comprising a molded layer of a substantially optically transparent material, the molded layer having first and second major surfaces configured such that light containing image information may propagate through and be guided within the molded layer by reflecting off the first and second major surfaces via total internal reflection. Equipped with The first surface includes a first smaller surface portion and a second larger surface portion monolithically integrated with the molded layer and with each other, the first smaller surface portion comprising at least a portion of a molded internal coupling optical element configured to couple light incident on the molded internal coupling optical element into the molded layer for propagation through the molded layer by reflection from the second major surface and the second larger surface portion of the first major surface. 14. A waveguide comprising: a polymer layer configured to propagate light containing image information therethrough; a plurality of surfaces sufficient to direct image information within the polymer layer by total internal reflection; a tilted surface portion, the tilted surface portion forming at least a portion of an incoupling optical element configured to deflect light containing image information within a waveguide; A waveguide comprising: 15. The waveguide of example 14, wherein the tilted surface portion forms a depression in the polymer layer. 16. The waveguide of example 15, wherein the depression in the polymer layer is at least 1 / 2 the thickness of the polymer layer. 17. The waveguide of example 15, wherein the depression in the polymer layer is at least 3 / 4 the thickness of the polymer layer. 18. The waveguide of any of Examples 14-17, wherein the tilted surface portion is tilted at about 40° to 50° relative to the plurality of surfaces. 19. The waveguide of any of Examples 14-18, wherein the internal coupling optical element comprises a turning mirror comprising a metallization. 20. The waveguide of any of Examples 14-19, wherein the tilted surface portion has a curvature to provide optical power. 21. The waveguide of any of Examples 14-20, wherein the polymer layer, the plurality of surfaces, and the tilted surface portion comprise molded optics. 22. The claim of any of Examples 14-21, wherein the plurality of surfaces have a surface roughness of about 0.1 nm to about 2.0 nm. 23. A waveguide comprising: an optically transparent layer comprising an optically transparent material and a plurality of surfaces sufficient to guide light containing image information within a waveguide by total internal reflection; a tilted surface portion forming at least a portion of an internal coupling optical element configured to deflect light containing image information within a waveguide such that the light is guided within the optically transparent layer, the tilted surface portion comprising a curvature to provide optical power; A waveguide comprising: 24. The waveguide of embodiment 23, wherein the optical power comprises a positive optical power. 25. The waveguide of any one of claims 23 to 24, wherein the tilted surface portion has a concave curvature from the perspective of most of the location within the optically transparent layer. 26. The waveguide of any of Examples 23-25, wherein the internal coupling optical element is a mirror, a facet, a prism, or a combination thereof. 27. The waveguide of any of Examples 23-26, wherein the internal coupling optical element further comprises a metal layer on the tilted surface portion. 28. The waveguide of any one of Examples 23-27, wherein each of the multiple surfaces has a surface roughness of about 0.1 nm to about 2.0 nm. 29. The waveguide of any of Examples 23-28, wherein the optically transparent material comprises a polymer. 30. The waveguide of any of Examples 23-29, wherein the optically transparent layer, the plurality of surfaces, and the tilted surface portion comprise molded optics. 31. A waveguide comprising: an optically transparent layer comprising an optically transparent material and first and second surfaces sufficient to guide light containing image information within a waveguide by total internal reflection; a surface portion on the first surface forming at least a portion of a lens, the surface portion being curved; A waveguide comprising: 32. The waveguide of example 31, wherein the lens comprises a convex lens. 33. The waveguide of any one of claims 31 to 32, wherein the lens comprises a positive power lens. 34. A waveguide as described in any of Examples 31-33, wherein the lens is aligned with the internal coupling optical element, and the internal coupling optical element is configured to rotate light received by the internal coupling optical element after passing through the lens and into the layer of optically transparent material so as to be guided within the layer of optically transparent material. 35. The waveguide of example 34, wherein the internal coupling optical element is disposed on the second surface of the layer of optically transparent material. 36. The waveguide of any one of Examples 31-35, wherein each of the multiple surfaces has a surface roughness of about 0.1 nm to about 2.0 nm. 37. The waveguide of any of Examples 31-36, wherein the optically transparent material comprises a polymer. 38. The waveguide of any of Examples 31-37, wherein the optically transparent layer, the first and second surfaces, and the lens comprise molded optics. 39. A waveguide comprising: an optically transparent layer comprising an optically transparent material and first and second surfaces sufficient to guide light containing image information within a waveguide by total internal reflection; a surface portion on the first surface forming at least a part of an anti-reflective structure, the anti-reflective structure comprising a surface relief pattern on the first surface; A waveguide comprising: 40. The waveguide of example 39, wherein the anti-reflective structure comprises an undulating pattern. 41. The waveguide of example 39 or example 40, wherein the anti-reflective structure comprises a periodic pattern. 42. The waveguide of example 41, wherein the periodic pattern has a period of about 50 nm to about 200 nm. 43. The waveguide of embodiment 41 or 42, wherein the periodic pattern has a height of about 5 nm to about 200 nm. 44. The waveguide of any of Examples 39-43, further comprising a material disposed on the surface relief pattern. 45. The waveguide of any of Examples 39-44, wherein the anti-reflection structure is optically aligned with an optical element associated with another waveguide. 46. ​​The waveguide of Example 45, wherein the optical element is an optical internal coupling element configured to couple light into the other waveguide. 47. The waveguide of any of Examples 39-46, wherein the first and second surfaces each have a surface roughness of about 0.1 nm to about 2.0 nm. 48. The waveguide of any of Examples 39-47, wherein the optically transparent material comprises a polymer. 49. The waveguide of any of Examples 39-48, wherein the optically transparent layer, the first and second surfaces, and the surface relief pattern comprise molded optics. 50. An optical system comprising one or more waveguides comprising the waveguide of any of Examples 1-49. 51. The optical system of Example 50, wherein the one or more waveguides comprise at least two waveguides described in any of Examples 1-49. 52. The optical system of embodiment 50 or 51, wherein the optical system is a head-mounted display system configured to project light to a user's eye and display augmented reality image content within the user's field of view. 53. A frame configured to be supported on a user's head; an image projector configured to project an image; an eyepiece disposed on the frame, the eyepiece configured to direct light into the user's eye and display augmented reality image content in the user's field of view, at least a portion of the eyepiece being transparent, the transparent portion being disposed at a location in front of the user's eye when the user wears the head mounted display system such that light from an environment in front of the user is transmitted to the user's eye to provide a view of the environment in front of the user, the eyepiece comprising the one or more waveguides; The optical system of Example 52, further comprising: 54. The optical system of example 53, wherein the image projector comprises a scanning fiber display. 55. A method of making a waveguide, the method comprising: providing a first and a second mold, the first and second molds facing each other, at least the first mold comprising an imprint of at least a portion of at least one internal coupling optical element; providing a polymeric material between the first mold and the second mold; contacting a polymeric material with the first and second dies such that the first die transfers a corresponding imprint of at least a portion of the at least one internal coupling optical element into the polymeric material; exposing the polymeric material to a hardening process; removing the polymeric material from the first and second molds; A method comprising: 56. The method of example 55, wherein exposing the polymeric material to a hardening process includes exposing the polymeric material to ultraviolet light. 57. The method of embodiment 55 or 56, wherein the waveguide comprises a plurality of surfaces sufficient to guide light containing image information within the waveguide by total internal reflection. 58. The method of example 57, wherein the multiple surfaces have a surface roughness of about 0.1 nm to about 2.0 nm. 59. The method of any of Examples 55-58, wherein at least one internal coupling optical element comprises a tilted surface. 60. The method of example 59, wherein the tilted surface has a curvature. 61. The method of any of Examples 55-60, wherein at least one internal coupling optical element comprises a lens. 62. The method of any of Examples 55-61, wherein at least one internal coupling optical element comprises a grating. The present invention provides, for example, the following: (Item 1) A waveguide comprising: A polymer layer comprising a substantially optically transparent material having first and second major surfaces configured such that light containing image information may propagate through and be guided within the polymer layer by reflecting off the first and second major surfaces via total internal reflection. Equipped with the first surface includes a first smaller surface portion and a second larger surface portion monolithically integrated with the polymer layer and with each other, the first smaller surface portion comprising at least a portion of an internal coupling optical element configured to couple light incident on the internal coupling optical element into the polymer layer for propagation through the polymer layer by reflection from the second major surface and the second larger surface portion of the first major surface. (Item 2) Item 2. The waveguide of item 1, wherein the internal coupling optical element comprises a turning mirror configured to deflect light containing image information within the waveguide. (Item 3) 3. The waveguide of claim 2, wherein the turning mirror comprises a second, larger surface portion of the first major surface and a first, smaller surface portion of the first major surface that is tilted relative to the second major surface. (Item 4) 4. The waveguide of claim 2 or 3, wherein the turning mirror has optical power. (Item 5) 5. The waveguide of claim 4, wherein the optically powered turning mirror comprises a second, larger surface portion of the first major surface and a first, smaller surface portion of the first major surface that is curved relative to the second major surface. (Item 6) 6. The waveguide of claim 2, wherein the turning mirror further comprises a metallization disposed on a first smaller surface portion of the first major surface. (Item 7) Item 2. The waveguide of item 1, wherein the internal coupling optical element comprises a lens. (Item 8) 8. The waveguide of claim 7, wherein the lens comprises a second, larger surface portion of the first major surface and a first, smaller surface portion of the first major surface that is curved relative to the second major surface. (Item 9) Item 2. The waveguide of item 1, wherein the internal coupling optical element comprises a grating. (Item 10) 10. The waveguide of claim 9, wherein the grating comprises a first smaller surface portion of the first major surface having an undulating surface relief. (Item 11) 11. The waveguide of any one of claims 1-10, wherein the polymer layer including at least a portion of the internal coupling optical element comprises a molded optic. (Item 12) Item 12. The waveguide according to any one of items 1-11, wherein the surfaces have a surface roughness of about 0.1 nm to about 2.0 nm. (Item 13) A waveguide comprising: 1. A molded optical system comprising a molded layer of a substantially optically transparent material, the molded layer having first and second major surfaces configured such that light containing image information may propagate through and be guided within the molded layer by reflecting off the first and second major surfaces via total internal reflection. Equipped with the first surface includes a first smaller surface portion and a second larger surface portion monolithically integrated with the molded layer and with each other, the first smaller surface portion comprising at least a portion of a molded internal coupling optical element configured to couple light incident on the molded internal coupling optical element into the molded layer for propagation through the molded layer by reflection from the second major surface and the second larger surface portion of the first major surface. (Item 14) A waveguide comprising: a polymer layer configured to propagate light containing image information therethrough; and a plurality of surfaces sufficient to direct the image information within the polymer layer by total internal reflection; a tilted surface portion, the tilted surface portion forming at least a portion of an incoupling optical element configured to deflect light containing image information within the waveguide; A waveguide comprising: (Item 15) Item 15. The waveguide of item 14, wherein the tilted surface portion forms a depression in the polymer layer. (Item 16) Item 16. The waveguide of item 15, wherein the depression in the polymer layer is at least ½ the thickness of the polymer layer. (Item 17) Item 16. The waveguide of item 15, wherein the depression in the polymer layer is at least 3 / 4 the thickness of the polymer layer. (Item 18) Item 18. The waveguide according to any one of items 14-17, wherein the tilted surface portion is tilted at an angle of about 40° to 50° relative to the plurality of surfaces. (Item 19) 19. The waveguide of any of claims 14-18, wherein the internal coupling optical element comprises a turning mirror comprising a metallization. (Item 20) 20. The waveguide of any one of claims 14-19, wherein the tilted surface portion has a curvature to provide optical power. (Item 21) 21. The waveguide of any one of claims 14-20, wherein the polymer layer, the plurality of surfaces, and the tilted surface portion comprise molded optics. (Item 22) 22. The waveguide according to any one of items 14-21, wherein the surfaces have a surface roughness of about 0.1 nm to about 2.0 nm. (Item 23) A waveguide comprising: an optically transparent layer comprising an optically transparent material and a plurality of surfaces sufficient to guide light containing image information within the waveguide by total internal reflection; a tilted surface portion, the tilted surface portion forming at least a portion of an internal coupling optical element configured to deflect light containing image information within the waveguide such that the light is guided within the optically transparent layer, the tilted surface portion comprising a curvature to provide optical power; A waveguide comprising: (Item 24) Item 24. The waveguide of item 23, wherein the optical power comprises a positive optical power. (Item 25) 25. The waveguide of claim 23 or 24, wherein the tilted surface portion has a concave curvature from a perspective mostly within the optically transparent layer. (Item 26) 26. The waveguide of any one of items 23-25, wherein the internal coupling optical element is a mirror, a facet, a prism, or a combination thereof. (Item 27) 27. The waveguide of any one of claims 23-26, wherein the internal coupling optical element further comprises a metal layer on the tilted surface portion. (Item 28) 28. The waveguide according to any one of items 23 to 27, wherein each of the plurality of surfaces has a surface roughness of about 0.1 nm to about 2.0 nm. (Item 29) 29. The waveguide of any of claims 23-28, wherein the optically transparent material comprises a polymer. (Item 30) 30. The waveguide of any one of claims 23-29, wherein the optically transparent layer, the plurality of surfaces, and the tilted surface portion comprise molded optics. (Item 31) A waveguide comprising: an optically transparent layer comprising an optically transparent material and first and second surfaces sufficient to guide light containing image information within the waveguide by total internal reflection; a surface portion on the first surface forming at least a portion of a lens, the surface portion being curved; A waveguide comprising: (Item 32) Item 32. The waveguide of item 31 , wherein the lens comprises a convex lens. (Item 33) Item 33. The waveguide of item 31 or 32, wherein the lens comprises a positive power lens. (Item 34) 34. The waveguide of any of claims 31-33, wherein the lens is aligned with an internal coupling optical element, the internal coupling optical element configured to rotate light received by the internal coupling optical element after passing through the lens and into the layer of optically transparent material so as to be guided within the layer of optically transparent material. (Item 35) Item 35. The waveguide of item 34, wherein the internal coupling optical element is disposed on a second surface of the layer of optically transparent material. (Item 36) 36. The waveguide according to any one of items 31 to 35, wherein each of the plurality of surfaces has a surface roughness of about 0.1 nm to about 2.0 nm. (Item 37) 37. The waveguide of any one of claims 31-36, wherein the optically transparent material comprises a polymer. (Item 38) 38. The waveguide of any one of claims 31-37, wherein the optically transparent layer, the first and second surfaces, and the lens comprise molded optics. (Item 39) A waveguide comprising: an optically transparent layer comprising an optically transparent material and first and second surfaces sufficient to guide light containing image information within the waveguide by total internal reflection; a surface portion on the first surface forming at least a part of an anti-reflective structure, the anti-reflective structure comprising a surface relief pattern on the first surface; A waveguide comprising: (Item 40) Item 40. The waveguide of item 39, wherein the anti-reflection structure comprises an undulating pattern. (Item 41) 41. The waveguide of claim 39, wherein the anti-reflection structure comprises a periodic pattern. (Item 42) Item 42. The waveguide according to item 41, wherein the periodic pattern has a period of about 50 nm to about 200 nm. (Item 43) Item 43. The waveguide according to item 41 or 42, wherein the periodic pattern has a height of about 5 nm to about 200 nm. (Item 44) 44. The waveguide of any of items 39-43, further comprising a material disposed on the surface relief pattern. (Item 45) 45. The waveguide of any one of claims 39-44, wherein the anti-reflection structure is optically aligned with an optical element associated with another waveguide. (Item 46) Item 46. The waveguide of item 45, wherein the optical element is an optical in-coupling element configured to couple light into the other waveguide. (Item 47) 47. The waveguide according to any one of items 39-46, wherein the first and second surfaces each have a surface roughness of about 0.1 nm to about 2.0 nm. (Item 48) 48. The waveguide of any one of claims 39-47, wherein the optically transparent material comprises a polymer. (Item 49) 49. The waveguide of any of claims 39-48, wherein the optically transparent layer, the first and second surfaces, and the surface relief pattern comprise molded optics. (Item 50) 50. An optical system comprising one or more waveguides comprising the waveguide according to any one of items 1-49. (Item 51) Item 51. The optical system of item 50, wherein the one or more waveguides comprise at least two waveguides of any of items 1-49. (Item 52) 52. The optical system of item 50 or 51, wherein the optical system is a head-mounted display system configured to project light to a user's eye and display augmented reality image content within the user's field of view. (Item 53) a frame configured to be supported on a head of the user; and an image projector configured to project an image; an eyepiece disposed on the frame, the eyepiece configured to direct light into the user's eye and display augmented reality image content in the user's field of view, at least a portion of the eyepiece being transparent, the transparent portion being disposed at a location in front of the user's eye when the user wears the head mounted display system such that light from an environment in front of the user is transmitted to the user's eye to provide a view of the environment in front of the user, the eyepiece comprising the one or more waveguides; Item 53. The optical system of item 52, further comprising: (Item 54) Item 54. The optical system of item 53, wherein the image projector comprises a scanning fiber display. (Item 55) 1. A method of making a waveguide, the method comprising: providing first and second molds, the first and second molds facing each other, at least the first mold comprising an imprint of at least a portion of at least one internal coupling optical element; providing a polymeric material between the first mold and the second mold; contacting the polymeric material with the first and second dies such that the first die transfers a corresponding imprint of at least a portion of the at least one internal coupling optical element into the polymeric material; exposing the polymeric material to a hardening process; removing the polymeric material from the first and second molds; A method comprising: (Item 56) 56. The method of claim 55, wherein exposing the polymeric material to a hardening process comprises exposing the polymeric material to ultraviolet light. (Item 57) 57. The method of claim 55 or 56, wherein the waveguide comprises a plurality of surfaces sufficient to guide light containing image information within the waveguide by total internal reflection. (Item 58) Item 58. The method of item 57, wherein the surfaces have a surface roughness of about 0.1 nm to about 2.0 nm. (Item 59) 59. The method of any of claims 55-58, wherein the at least one internal coupling optical element comprises a tilted surface. (Item 60) Item 60. The method of item 59, wherein the tilted surface has a curvature. (Item 61) 61. The method of any of claims 55-60, wherein the at least one internal coupling optical element comprises a lens. (Item 62) 62. The method of any of claims 55-61, wherein the at least one internal coupling optical element comprises a grating. [Brief description of the drawings]

[0008] [Figure 1] FIG. 1 illustrates a user's view of an augmented reality (AR) device.

[0009] [Diagram 2]FIG. 2 illustrates a conventional display system for simulating a three-dimensional image for a user.

[0010] [Diagram 3] 3A-3C illustrate the relationship between the radius of curvature and the radius of focus.

[0011] [Figure 4A] FIG. 4A illustrates a representation of the accommodation-vergence response of the human visual system.

[0012] [Figure 4B] FIG. 4B illustrates examples of different accommodation and convergence states of a pair of eyes of a user.

[0013] [Figure 4C] FIG. 4C illustrates an example of a top-down view representation of a user viewing content through a display system.

[0014] [Figure 4D] FIG. 4D illustrates another example of a top-down view representation of a user viewing content through a display system.

[0015] [Diagram 5] FIG. 5 illustrates aspects of an approach for simulating a three-dimensional image by modifying wavefront divergence.

[0016] [Figure 6] FIG. 6 illustrates an embodiment of a waveguide stack for outputting image information to a user.

[0017] [Figure 7] FIG. 7 illustrates an example of an output beam output by a waveguide.

[0018] [Figure 8]FIG. 8 illustrates an example of a stacked waveguide assembly in which each depth plane contains an image formed using multiple different primary colors.

[0019] [Figure 9A] FIG. 9A illustrates a cross-sectional side view of an example of a set of stacked waveguides, each of which includes an internal coupling optical element.

[0020] [Figure 9B] FIG. 9B illustrates a perspective view of the multiple stacked waveguide embodiment of FIG. 9A.

[0021] [Figure 9C] FIG. 9C illustrates a top-down plan view of the multiple stacked waveguide embodiment of FIGS. 9A and 9B.

[0022] [Figure 9D] FIG. 9D illustrates an example of a wearable display system.

[0023] [Figure 10] 10, 11, 12, 13, 14, 15, and 16 illustrate exemplary waveguides with integrated incoupling optical elements. [Figure 11] 10, 11, 12, 13, 14, 15, and 16 illustrate exemplary waveguides with integrated incoupling optical elements. [Figure 12] 10, 11, 12, 13, 14, 15, and 16 illustrate exemplary waveguides with integrated incoupling optical elements. [Figure 13] 10, 11, 12, 13, 14, 15, and 16 illustrate exemplary waveguides with integrated incoupling optical elements. [Figure 14] 10, 11, 12, 13, 14, 15, and 16 illustrate exemplary waveguides with integrated incoupling optical elements. [Figure 15] 10, 11, 12, 13, 14, 15, and 16 illustrate exemplary waveguides with integrated incoupling optical elements. [Figure 16] 10, 11, 12, 13, 14, 15, and 16 illustrate exemplary waveguides with integrated incoupling optical elements.

[0024] [Figure 16A] 16A and 16B show magnified images of an exemplary anti-reflective structure adjacent to an exemplary incoupling optical element. [Figure 16B] 16A and 16B show magnified images of an exemplary anti-reflective structure adjacent to an exemplary incoupling optical element.

[0025] [Figure 17A] 17A, 17B, 17C, and 17D illustrate an exemplary method of forming a waveguide with integrated optical elements. [Figure 17B] 17A, 17B, 17C, and 17D illustrate an exemplary method of forming a waveguide with integrated optical elements. [Figure 17C] 17A, 17B, 17C, and 17D illustrate an exemplary method of forming a waveguide with integrated optical elements. [Figure 17D] 17A, 17B, 17C, and 17D illustrate an exemplary method of forming a waveguide with integrated optical elements. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0026] Waveguides may be utilized to direct light within display devices, including head-mounted augmented reality display systems, and the like. For example, a waveguide may be incorporated into a pair of glasses, and a viewer may view the surrounding environment through the waveguide. In addition, a waveguide may project an image by receiving light containing image information (e.g., by a projector system) and directing the light into the viewer's eye. The received light may be incoupling into the waveguide using an incoupling optical element. The incoupling light may then be dispersed within the waveguide using an optical dispersion element, and outcoupling out of the waveguide using an outcoupling element.

[0027] Low coupling efficiency of light between the projector system and the waveguide can reduce the total efficiency of the waveguide assembly and can degrade the overall image quality provided to the viewer. Coupling between optical components can also add constraints to the manufacturing of the display device and / or system (e.g., constraints on how to integrate, assemble, align, and package with other components). Thus, internal coupling optical elements can affect the design.

[0028] The incoupling optical element can include a conventional grating, which may have a relatively low incoupling efficiency of the incident light from the projector. Conventional gratings can also reflect light back into the projector, which may be reflected back into the grating from the projector. Stray light paths can produce persistence image artifacts that can be disturbing. Conventional gratings can also have inherently different diffraction efficiencies versus input angle. In various waveguide displays, this can make it difficult to produce images with uniform brightness. Nevertheless, sometimes incoupling gratings can be desirable. Prisms and lenses can also be inherently optically advantageous, but can be difficult to fabricate and integrate.

[0029] Certain implementations described herein may include a waveguide with an integrated in-coupling optical element. For example, various waveguides may include a surface that forms at least a portion of the in-coupling optical element. Compared to a waveguide without such an in-coupling optical element integrated with the waveguide, various implementations may advantageously provide higher coupling efficiency, better image quality (e.g., lower residual light, higher uniformity, etc.), and a simpler manufacturing process. For example, in various implementations, the integrated optical element may allow direct contact with the waveguide, leading to increased in-coupling and simpler integration. Certain implementations may advantageously integrate prisms, lenses, and / or anti-reflection structures. Various implementations may reduce residual light image artifacts, achieve more uniform brightness, and reduce the total footprint of the device. Some implementations of the waveguide may also integrate one or more other optical elements, such as a light dispersing element and / or an out-coupling optical element.

[0030] Reference will now be made to the drawings in which like reference numbers refer to like parts throughout. Unless otherwise indicated, the drawings are schematic and are not necessarily drawn to scale. (Exemplary Display System)

[0031] FIG. 2 illustrates a conventional display system for simulating a three-dimensional image for a user. It should be understood that when a user's eyes are spaced apart and viewing a real object in space, each eye may have a slightly different view of the object and form an image of the object at a different location on each eye's retina. This may be referred to as binocular disparity and may be exploited by the human visual system to provide a perception of depth. Conventional display systems simulate binocular disparity by presenting two distinctly different images 190, 200 with slightly different views of the same virtual object, one for each eye 210, 220, corresponding to the view of the virtual object as it would appear by each eye as if the virtual object were a real object at a desired depth. These images provide binocular cues that the user's visual system may interpret to derive a perception of depth.

[0032] Continuing with reference to FIG. 2, the images 190, 200 are spaced from the eyes 210, 220 by a distance 230 on the z-axis, which is parallel to the optical axis of the viewer when that eye is fixating on an object at optical infinity directly in front of the viewer. The images 190, 200 are flat and at a fixed distance from the eyes 210, 220. Based on slightly different views of the virtual object in the images presented to the eyes 210, 220, respectively, the eyes may naturally rotate such that the image of the object falls on a corresponding point on the eye's respective retina, maintaining single binocular vision. This rotation may cause the line of sight of each of the eyes 210, 220 to converge on a point in space where the virtual object is perceived to reside. As a result, providing three-dimensional images traditionally involves manipulating the convergence and divergence movements of the user's eyes 210, 220 to provide binocular cues that the human visual system interprets to provide the perception of depth.

[0033] However, creating a realistic and comfortable perception of depth is difficult. It should be understood that light from an object at different distances from the eye has a wavefront with different amounts of divergence. Figures 3A-3C illustrate the relationship between distance and divergence of light rays. The distance between the object and the eye 210 is represented in the order of decreasing distances R1, R2, and R3. As shown in Figures 3A-3C, the light rays become more divergent as the distance to the object decreases. Conversely, as the distance increases, the light rays become more collimated. In other words, the light field generated by a point (an object or part of an object) can be said to have a spherical wavefront curvature that is a function of the distance the point is away from the user's eye. The curvature increases with decreasing distance between the object and the eye 210. Although only a single eye 210 is illustrated in Figures 3A-3C and various other figures herein for clarity of illustration, the discussion regarding the eye 210 may apply to both eyes 210 and 220 of a viewer.

[0034] 3A-3C, light from an object that a viewer's eye is fixating on may have different wavefront divergences. Due to the different wavefront divergences, the light may be focused differently by the eye's lens, which in turn may require the lens to assume a different shape and form a focused image on the eye's retina. If a focused image is not formed on the retina, the resulting retinal blur acts as an accommodative cue, causing the shape of the eye's lens to change until a focused image is formed on the retina. For example, the accommodative cue may induce relaxation or contraction of the ciliary muscle surrounding the eye's lens, thereby modulating the force applied to the suspensory ligament that holds the lens, thus changing the shape of the eye's lens, thereby forming a focused image of the fixated object on the eye's retina (e.g., fovea) until retinal blur of the fixated object is eliminated or minimized. The process by which the eye lens changes shape may be referred to as accommodation, and the shape of the eye lens required to form a focused image of a fixated object on the eye's retina (e.g., the fovea) may be referred to as the state of accommodation.

[0035] Referring now to FIG. 4A, a representation of the accommodation-vergence response of the human visual system is illustrated. A movement of the eye to fixate an object causes the eye to receive light from the object, which forms an image on each of the eye's retinas. The presence of retinal blur in the image formed on the retina may provide a cue for accommodation, and the relative location of the image on the retina may provide a cue for vergence. The accommodation cue causes accommodation and causes the eye's lens to assume a particular accommodation state that forms a focused image of the object on the eye's retina (e.g., the fovea). On the other hand, the vergence cue causes a vergence movement (eye rotation) such that the image formed on each retina of each eye is at a corresponding retinal point that maintains single binocular vision. In these positions, the eyes may be said to be in a particular vergence state. Continuing with reference to FIG. 4A, accommodation can be understood to be the process by which the eye achieves a particular accommodation state, and convergence can be understood to be the process by which the eye achieves a particular convergence state. As shown in FIG. 4A, the accommodation and convergence state of the eye can change when the user fixates a different object. For example, the accommodated state can change when the user fixates a new object at a different depth on the z-axis.

[0036] Without being limited by theory, it is believed that a viewer of an object may perceive the object as "three-dimensional" due to a combination of vergence-divergence and accommodation. As noted above, vergence-divergence movements of the two eyes relative to one another (e.g., rotation of the eyes such that the pupils move toward or away from one another, converging the gaze of the eyes to fixate on the object) are closely coupled to accommodation of the eye's lenses. Under normal conditions, changing the shape of the eye's lenses and shifting the focus from one object to another at a different distance will automatically produce a corresponding change in vergence-divergence at the same distance, a relationship known as the "accommodation-vergence-divergence reflex." Similarly, a change in vergence-divergence will induce a corresponding change in lens shape under normal conditions.

[0037] 4B, an example of different accommodation and convergence states of the eyes is illustrated. The pair of eyes 222a fixates an object at optical infinity, while the pair of eyes 222b fixates an object 221 at less than optical infinity. Notably, the convergence states of each pair of eyes are different, with the pair of eyes 222a pointing straight ahead, while the pair of eyes 222 converge on the object 221. The accommodation states of the eyes forming each pair of eyes 222a and 222b are also different, as represented by the different shapes of the lenses 210a, 220a.

[0038] Unfortunately, many users of conventional "3-D" display systems may find such conventional systems uncomfortable or may not perceive any depth sensation due to a mismatch between accommodation and vergence states in these displays. As noted above, many stereoscopic or "3-D" display systems display a scene by providing a slightly different image to each eye. Such systems are uncomfortable for many viewers because, among other things, they simply provide different presentations of a scene, causing changes in the vergence states of the eyes, but without a corresponding change in the accommodation states of those eyes. Rather, images are presented by the display at a fixed distance from the eyes, such that the eyes view all image information in a single accommodation state. Such an arrangement counters the "accommodation-vergence-divergence reflex" by causing changes in vergence states without a corresponding change in accommodation state. This mismatch is believed to cause viewer discomfort. Display systems that provide a better match between accommodation and convergence-divergence movements may produce a more realistic and comfortable simulation of a three-dimensional image.

[0039] Without being limited by theory, it is believed that the human eye may typically interpret a finite number of depth planes to provide depth perception. As a result, a highly realistic simulation of perceived depth may be achieved by providing the eye with different presentations of images corresponding to each of these limited number of depth planes. In some embodiments, the different presentations may provide both vergence cues and matching cues for accommodation, thereby providing a physiologically correct accommodation-vergence divergence match.

[0040] 4B, two depth planes 240 are illustrated, corresponding to different distances in space from the eyes 210, 220. For a given depth plane 240, vergence-divergence cues may be provided by displaying appropriately different perspective images for each eye 210, 220. Additionally, for a given depth plane 240, the light forming the image provided to each eye 210, 220 may have a wavefront divergence corresponding to the light field generated by a point at the distance of that depth plane 240.

[0041] In the illustrated embodiment, the distance along the z-axis of the depth plane 240 containing the point 221 is 1 m. As used herein, the distance or depth along the z-axis may be measured with the zero point located at the exit pupil of the user's eye. Thus, the depth plane 240 located at a depth of 1 m corresponds to a distance of 1 m away from the exit pupil of the user's eye on the optical axis of those eyes with the eyes pointed towards optical infinity. As an approximation, the depth or distance along the z-axis may be measured from the display in front of the user's eye (e.g., from the surface of the waveguide) and a value for the distance between the device and the exit pupil of the user's eye may be added. That value may be called the pupil distance and may correspond to the distance between the exit pupil of the user's eye and the display worn by the user in front of the eye. In practice, the value for the pupil distance may be a normalized value that is generally used for all viewers. For example, the pupil distance may be assumed to be 20 mm and the depth plane at a depth of 1 m may be at a distance of 980 mm in front of the display.

[0042] 4C and 4D, examples of matched accommodation-vergence-divergence distances and mismatched accommodation-vergence-divergence distances are illustrated, respectively. As illustrated in FIG. 4C, the display system may provide an image of a virtual object to each eye 210, 220. The image may cause the eyes 210, 220 to assume a vergence-divergence state in which the eyes converge on point 15 on the depth plane 240. In addition, the image may be formed by light having a wavefront curvature corresponding to a real object in that depth plane 240. As a result, the eyes 210, 220 assume an accommodation state in which the image focuses on the retinas of those eyes. Thus, the user may perceive the virtual object as being at point 15 on the depth plane 240.

[0043] It should be appreciated that each of the accommodation and convergence states of the eyes 210, 220 is associated with a particular distance on the z-axis. For example, an object at a particular distance from the eyes 210, 220 will cause those eyes to assume a particular accommodation state based on the distance of the object. The distance associated with a particular accommodation state is referred to as the accommodation distance A. d Similarly, a particular convergence-divergence distance V associated with the eyes in a particular convergence-divergence state or position relative to one another may be referred to as d If the accommodation distance and the vergence distance match, the relationship between accommodation and vergence is said to be physiologically correct. This is considered to be the most comfortable scenario for the viewer.

[0044] However, in a stereoscopic display, the accommodation distance and the vergence distance may not always coincide. For example, as illustrated in FIG. 4D, the image displayed to the eyes 210, 220 may be displayed with a wavefront divergence corresponding to the depth plane 240, and the eyes 210, 220 may be in a particular accommodation state in which the points 15a, 15b on the depth plane are focused. However, the image displayed to the eyes 210, 220 may provide a cue for vergence that causes the eyes 210, 220 to converge on a point 15 that is not located on the depth plane 240. As a result, the accommodation distance corresponds in some embodiments to the distance from the exit pupils of the eyes 210, 220 to the depth plane 240, while the vergence distance corresponds to a larger distance from the exit pupils of the eyes 210, 220 to the point 15. The accommodation distance is different from the vergence distance. As a result, there is an accommodation-vergence-divergence mismatch. Such a mismatch may be considered undesirable and may cause discomfort to the user. The mismatch may be related to the distance (e.g., V d -A d ) and can be characterized in terms of diopters.

[0045] It should be understood that in some embodiments, reference points other than the exit pupils of the eyes 210, 220 may be utilized to determine distances for determining accommodation-vergence mismatch, so long as the same reference points are utilized for accommodation distance and vergence distance. For example, distances may be measured from the cornea to the depth plane, from the retina to the depth plane, from the eyepiece (e.g., a waveguide in a display device) to the depth plane, etc.

[0046] Without being limited by theory, it is believed that a user may still perceive an accommodation-vergence-divergence mismatch of up to about 0.25 diopters, up to about 0.33 diopters, and up to about 0.5 diopters as physiologically correct, without the mismatch itself causing significant discomfort. In some embodiments, a display system disclosed herein (e.g., display system 250, FIG. 6) presents an image to a viewer having an accommodation-vergence-divergence mismatch of about 0.5 diopters or less. In some other embodiments, the accommodation-vergence-divergence mismatch of the image provided by the display system is about 0.33 diopters or less. In still other embodiments, the accommodation-vergence-divergence mismatch of the image provided by the display system is about 0.25 diopters or less, including about 0.1 diopters or less.

[0047] FIG. 5 illustrates aspects of an approach for simulating a three-dimensional image by modifying the wavefront divergence. The display system includes a waveguide 270 configured to receive light 770 encoded with image information and output the light to a user's eye 210. The waveguide 270 may output light 650 with a defined amount of wavefront divergence that corresponds to the wavefront divergence of a light field generated by a point on a desired depth plane 240. In some embodiments, the same amount of wavefront divergence is provided for all objects presented on that depth plane. In addition, it will be illustrated that the user's other eye may be provided with image information from a similar waveguide.

[0048] In some embodiments, a single waveguide may be configured to output light with a set wavefront divergence corresponding to a single or limited number of depth planes, and / or the waveguide may be configured to output light of a limited range of wavelengths. As a result, in some embodiments, multiple or stacked waveguides may be utilized to provide different wavefront divergence for different depth planes and / or output light of different ranges of wavelengths. As used herein, it should be understood that a depth plane may follow the contour of a flat or curved surface. In some embodiments, advantageously and for simplicity, a depth plane may follow the contour of a flat surface.

[0049] 6 illustrates an example of a waveguide stack for outputting image information to a user. The display system 250 includes a stack of waveguides or a stacked waveguide assembly 260 that can be utilized to provide a three-dimensional perception to the eye / brain using multiple waveguides 270, 280, 290, 300, 310. It should be understood that the display system 250 can be considered a light field display in some embodiments. Additionally, the waveguide assembly 260 can also be referred to as an eyepiece.

[0050] In some embodiments, the display system 250 may be configured to provide a substantially continuous cue for convergence and multiple discrete cues for accommodation. The cues for convergence may be provided by displaying a different image to each of the user's eyes, and the cues for accommodation may be provided by outputting light forming an image with a selectable discrete amount of wavefront divergence. In other words, the display system 250 may be configured to output light with variable levels of wavefront divergence. In some embodiments, each discrete level of wavefront divergence corresponds to a particular depth plane and may be provided by a particular one of the waveguides 270, 280, 290, 300, 310.

[0051] Continuing with reference to FIG. 6, the waveguide assembly 260 may also include a number of features 320, 330, 340, 350 between the waveguides. In some embodiments, the features 320, 330, 340, 350 may be one or more lenses. The waveguides 270, 280, 290, 300, 310 and / or the number of lenses 320, 330, 340, 350 may be configured to transmit image information to the eye with various levels of wavefront curvature or light beam divergence. Each waveguide level may be associated with a particular depth plane and may be configured to output image information corresponding to that depth plane. The image input devices 360, 370, 380, 390, 400 may act as light sources for the waveguides and may be utilized to input image information into the waveguides 270, 280, 290, 300, 310, which may each be configured to disperse incident light across each individual waveguide for output towards the eye 210, as described herein. Light exits output surfaces 410, 420, 430, 440, 450 of the image input devices 360, 370, 380, 390, 400 and is input into corresponding input surfaces 460, 470, 480, 490, 500 of the waveguides 270, 280, 290, 300, 310. In some embodiments, each of the input surfaces 460, 470, 480, 490, 500 may be an edge of the corresponding waveguide or a portion of a major surface of the corresponding waveguide (i.e., one of the waveguide surfaces that directly faces the world 510 or the viewer's eye 210). In some embodiments, a single beam of light (e.g., a collimated beam) may be launched into each waveguide and output an entire field of cloned collimated beams that are directed toward the eye 210 at a particular angle (and divergence) corresponding to the depth plane associated with the particular waveguide. In some embodiments, a single one of the image launch devices 360, 370, 380, 390, 400 may be associated with and launch light into multiple (e.g., three) waveguides 270, 280, 290, 300, 310.

[0052] In some embodiments, the image input devices 360, 370, 380, 390, 400 are discrete displays that each generate image information for input into a corresponding waveguide 270, 280, 290, 300, 310. In some other embodiments, the image input devices 360, 370, 380, 390, 400 are outputs of a single multiplexed display that may send image information to each of the image input devices 360, 370, 380, 390, 400, for example, via one or more optical conduits (such as fiber optic cables). It should be understood that the image information provided by the image input devices 360, 370, 380, 390, 400 may include light of different wavelengths or colors (e.g., different primary colors as discussed herein).

[0053] In some embodiments, the light injected into the waveguides 270, 280, 290, 300, 310 is provided by a light projector system 520 comprising a light module 530, which may include light emitters such as light emitting diodes (LEDs). Light from the light module 530 may be directed through a beam splitter 550 to and modified by a light modulator 540, e.g., a spatial light modulator. The light modulator 540 may be configured to vary the perceived intensity of the light injected into the waveguides 270, 280, 290, 300, 310 and encode the light with image information. Examples of spatial light modulators include liquid crystal displays (LCDs), including liquid crystal on silicon (LCOS) displays. It should be understood that image injection devices 360, 370, 380, 390, 400 are illustrated diagrammatically and in some embodiments these image injection devices may represent different light paths and locations within a common projection system configured to output light into associated ones of waveguides 270, 280, 290, 300, 310. In some embodiments, the waveguides of the waveguide assembly 260 may act as ideal lenses, relaying light injected into the waveguides to the user's eye. In this concept, the object may be a spatial light modulator 540 and the image may be an image on a depth plane.

[0054] In some embodiments, the display system 250 may be a scanning fiber display comprising one or more scanning fibers configured to project light in various patterns (e.g., raster scan, spiral scan, Lissajous pattern, etc.) into one or more waveguides 270, 280, 290, 300, 310 and ultimately to the viewer's eye 210. In some embodiments, the illustrated image injection devices 360, 370, 380, 390, 400 may represent diagrammatically a single scanning fiber or a bundle of scanning fibers configured to inject light into one or more waveguides 270, 280, 290, 300, 310. In some other embodiments, the illustrated image injection devices 360, 370, 380, 390, 400 may represent diagrammatically multiple scanning fibers or multiple bundles of scanning fibers configured to inject light into associated ones of the waveguides 270, 280, 290, 300, 310, respectively. It should be understood that one or more optical fibers may be configured to transmit light from the optical module 530 to one or more of the waveguides 270, 280, 290, 300, 310. It should be understood that one or more intervening optical structures may be provided between the scanning fiber or fibers and one or more of the waveguides 270, 280, 290, 300, 310, for example, to redirect light exiting the scanning fiber into one or more of the waveguides 270, 280, 290, 300, 310.

[0055] The controller 560 controls the operation of one or more of the stacked waveguide assemblies 260, including the operation of the image input devices 360, 370, 380, 390, 400, the light source 530, and the light modulator 540. In some embodiments, the controller 560 is part of the local data processing module 140. The controller 560 includes programming (e.g., instructions in a non-transient medium) that coordinates the timing and provision of image information to the waveguides 270, 280, 290, 300, 310, for example, according to any of the various schemes disclosed herein. In some embodiments, the controller may be a single integrated device or a distributed system connected by wired or wireless communication channels. The controller 560 may be part of the processing module 140 or 150 (FIG. 9D) in some embodiments.

[0056] Continuing with reference to FIG. 6, the waveguides 270, 280, 290, 300, 310 may be configured to propagate light within each individual waveguide by total internal reflection (TIR). Each of the waveguides 270, 280, 290, 300, 310 may be planar or have another shape (e.g., curved) with major top and bottom surfaces and edges extending between the major top and bottom surfaces. In the illustrated configuration, each of the waveguides 270, 280, 290, 300, 310 may include an outcoupling optical element 570, 580, 590, 600, 610 configured to extract light from the waveguide by redirecting light propagating within each individual waveguide out of the waveguide and outputting image information to the eye 210. The extracted light may also be referred to as outcoupling light, and the outcoupling optical element light may also be referred to as a light extraction optical element. The extracted beam of light may be output by the waveguide at a location where the light propagating within the waveguide strikes the light extraction optical element. The outcoupling optical element 570, 580, 590, 600, 610 may be a grating, for example, including diffractive optical features as further discussed herein. Although shown disposed on the bottom major surface of the waveguide 270, 280, 290, 300, 310 for ease of explanation and clarity of drawing, in some embodiments the outcoupling optical element 570, 580, 590, 600, 610 may be disposed on the top major surface and / or bottom major surface and / or directly within the volume of the waveguide 270, 280, 290, 300, 310, as further discussed herein. In some embodiments, the outcoupling optical elements 570, 580, 590, 600, 610 may be formed within a layer of material attached to a transparent substrate and forming the waveguide 270, 280, 290, 300, 310. In some other embodiments, the waveguide 270, 280, 290, 300, 310 may be a monolithic material component and the outcoupling optical elements 570, 580, 590, 600, 610 may be formed on a surface and / or within the material component. As described herein, in some embodiments, the outcoupling optical elements 570, 580, 590, 600, 610 may be integrated with a surface portion of the waveguide 270, 280, 290, 300, 310.

[0057] With continued reference to FIG. 6, as discussed herein, each waveguide 270, 280, 290, 300, 310 is configured to output light and form an image corresponding to a particular depth plane. For example, the waveguide 270 closest to the eye may be configured to deliver collimated light (injected into such waveguide 270) to the eye 210. The collimated light may represent an optical infinity focal plane. The next upper waveguide 280 may be configured to send collimated light that passes through a first lens 350 (e.g., a negative lens) before it can reach the eye 210. Such a first lens 350 may be configured to generate a slight convex wavefront curvature such that the eye / brain interprets the light originating from the next upper waveguide 280 as originating from a first focal plane closer inward from optical infinity toward the eye 210. Similarly, the third upper waveguide 290 passes its output light through both the first lens and the second lens 340 and 350 before reaching the eye 210. The combined refractive power of the first lens 350 and the second lens 340 may be configured to produce another incremental amount of wavefront curvature such that the eye / brain interprets the light emerging from the third waveguide 290 as originating from a second focal plane that is closer inward from optical infinity towards the person than was the light from the next upper waveguide 280.

[0058] The other waveguide layers 300, 310 and lenses 330, 320 are similarly configured, with the highest waveguide 310 in the stack sending its output through all of the lenses between it and the eye for an aggregate focal power that represents the focal plane closest to the person. To compensate the stack of lenses 320, 330, 340, 350 when viewing / interpreting light originating from the world 510 on the other side of the stacked waveguide assembly 260, a compensating lens or lens layer 620 may be placed on top of the stack to compensate for the aggregate power of the lens stacks 320, 330, 340, 350 below. Such a configuration provides as many perceived focal planes as there are waveguide / lens pairs available. Both the outcoupling optical elements of the waveguides and the focusing sides of the lenses may be static (i.e., not dynamic or electroactive). In some alternative embodiments, either or both may be dynamic using electroactive features.

[0059] In some embodiments, two or more of the waveguides 270, 280, 290, 300, 310 may have the same associated depth plane. For example, multiple waveguides 270, 280, 290, 300, 310 may be configured to output images set at the same depth plane, or multiple subsets of the waveguides 270, 280, 290, 300, 310 may be configured to output images set at the same depth planes, with one set per depth plane. This may provide an advantage for forming tiled images to provide an extended field of view at those depth planes.

[0060] Continuing with reference to FIG. 6, the outcoupling optical elements 570, 580, 590, 600, 610 may be configured to redirect light out of their respective waveguides and output the light with an appropriate amount of divergence or collimation for the particular depth planes associated with the waveguides. As a result, waveguides with different associated depth planes may have different configurations of outcoupling optical elements 570, 580, 590, 600, 610 that output light with different amounts of divergence depending on the associated depth plane. In some embodiments, the light extraction optical elements 570, 580, 590, 600, 610 may be volume or surface features that may be configured to output light at specific angles. For example, the light extraction optical elements 570, 580, 590, 600, 610 may be volume holograms, surface holograms, and / or diffraction gratings. In some embodiments, the light extraction optical elements 570 , 580 , 590 , 600 , 610 may be gratings that are integrated with surface portions of the waveguides 270 , 280 , 290 , 300 , 310 .

[0061] In some embodiments, the outcoupling optical elements 570, 580, 590, 600, 610 are diffractive features or "diffractive optical elements" (also referred to herein as "DOEs") that form a diffraction pattern. Preferably, the DOEs have a sufficiently low diffraction efficiency so that only a portion of the light in the beam is deflected toward the eye 210 at each intersection of the DOE, while the remainder continues to travel through the waveguide via TIR. The light carrying the image information is thus split into several related exit beams that exit the waveguide at multiple locations, resulting in a very uniform pattern of exit emission toward the eye 210 for this particular collimated beam bouncing within the waveguide.

[0062] In some embodiments, one or more DOEs may be switchable between an "on" state in which they actively diffract and an "off" state in which they do not significantly diffract. For example, a switchable DOE may comprise a layer of polymer dispersed liquid crystal in which microdroplets comprise a diffractive pattern within a host medium, and the refractive index of the microdroplets may be switched to substantially match the refractive index of the host material (in which case the pattern does not significantly diffract incident light), or the microdroplets may be switched to a refractive index that does not match that of the host medium (in which case the pattern actively diffracts incident light).

[0063] In some embodiments, a camera assembly 630 (e.g., a digital camera, including visible and infrared light cameras) may be provided to capture images of the eye 210 and / or tissue surrounding the eye 210, for example, to detect user input and / or monitor a physiological condition of the user. As used herein, a camera may be any image capture device. In some embodiments, the camera assembly 630 may include an image capture device and a light source that projects light (e.g., infrared light) onto the eye, which may then be reflected by the eye and detected by the image capture device. In some embodiments, the camera assembly 630 may be mounted to the frame 80 (FIG. 9D) and may be in electrical communication with the processing modules 140 and / or 150, which may process image information from the camera assembly 630. In some embodiments, one camera assembly 630 may be utilized per eye, monitoring each eye separately.

[0064] 7, an example of an output beam output by a waveguide is shown. Although one waveguide is shown, it should be understood that other waveguides in the waveguide assembly 260 (FIG. 6) may function similarly and that the waveguide assembly 260 includes multiple waveguides. Light 640 is launched into the waveguide 270 at the input surface 460 of the waveguide 270 and propagates within the waveguide 270 by TIR. At the point where the light 640 impinges on the DOE 570, a portion of the light exits the waveguide as an output beam 650. The output beams 650 are shown as approximately parallel, but as discussed herein, they may also be redirected to propagate to the eye 210 at an angle (e.g., to form a diverging output beam) depending on the depth plane associated with the waveguide 270. It should be understood that a nearly collimated exit beam may refer to a waveguide with outcoupling optics that outcouples light to form an image that appears to be set on a depth plane at a large distance (e.g., optical infinity) from the eye 210. Other waveguides or other sets of outcoupling optics may output a more divergent exit beam pattern, which would require the eye 210 to accommodate to a closer distance and focus on the retina, and would be interpreted by the brain as light from a distance closer to the eye 210 than optical infinity.

[0065] In some embodiments, a full color image may be formed at each depth plane by overlaying an image in each of the primary colors, for example, three or more primary colors. FIG. 8 illustrates an example of a stacked waveguide assembly in which each depth plane includes an image formed using multiple different primary colors. The illustrated embodiment shows depth planes 240a-240f, but more or less depths are also contemplated. Each depth plane may have three or more primary color images associated with it, including a first image of a first color G, a second image of a second color R, and a third image of a third color B. The different depth planes are indicated in the figure by different numbers for diopters (dpt) following the letters G, R, and B. Merely by way of example, the numbers following each of these letters indicate the diopters (1 / m), i.e., the inverse distance of the depth plane from the viewer, and each box in the figure represents an individual primary color image. In some embodiments, the exact location of the depth planes for the different primary colors may be varied to account for differences in the eye's focusing of light of different wavelengths. For example, different primary color images for a given depth plane may be placed on depth planes that correspond to different distances from the user. Such an arrangement may increase visual acuity and user comfort, and / or reduce chromatic aberration.

[0066] In some embodiments, light of each primary color may be output by a single dedicated waveguide, such that each depth plane may have multiple waveguides associated with it. In such embodiments, each box in the figure containing the letter G, R, or B may be understood to represent an individual waveguide, and three waveguides may be provided per depth plane, with three primary color images provided per depth plane. The waveguides associated with each depth plane are shown adjacent to each other in this drawing for ease of illustration, but it should be understood that in a physical device, the waveguides may all be arranged in a stack with one waveguide per level. In some other embodiments, multiple primary colors may be output by the same waveguide, such that, for example, only a single waveguide may be provided per depth plane.

[0067] 8, in some embodiments, G is green, R is red, and B is blue. In some other embodiments, other colors associated with other wavelengths of light, including magenta and cyan, may be used in addition to or in place of one or more of red, green, or blue.

[0068] It should be understood that references throughout this disclosure to a given color of light will be understood to encompass one or more wavelengths of light within the range of wavelengths of light that are perceived by a viewer as being of that given color. For example, red light may include one or more wavelengths of light within a range of about 620-780 nm, green light may include one or more wavelengths of light within a range of about 492-577 nm, and blue light may include one or more wavelengths of light within a range of about 435-493 nm.

[0069] In some embodiments, the light source 530 (FIG. 6) may be configured to emit light at one or more wavelengths outside the range of visual perception of a viewer, e.g., infrared and / or ultraviolet wavelengths. Additionally, the waveguide in-coupling, out-coupling, and other light redirecting structures of the display 250 may be configured to direct and emit this light from the display toward the user's eye 210, e.g., for imaging and / or user stimulation applications.

[0070] 9A, in some embodiments, light impinging on a waveguide may need to be redirected to in-couple the light into the waveguide. An in-coupling optical element may be used to redirect and in-couple the light into its corresponding waveguide. FIG. 9A illustrates a cross-sectional side view of an example of a plurality or set 660 of stacked waveguides, each including an in-coupling optical element. The waveguides may each be configured to output light of one or more different wavelengths or one or more different wavelength ranges. It should be understood that the stack 660 may correspond to the stack 260 (FIG. 6), and that the illustrated waveguides of the stack 660 may correspond to a portion of the plurality of waveguides 270, 280, 290, 300, 310, except that light from one or more of the image input devices 360, 370, 380, 390, 400 is input into the waveguide from a position that requires the light to be redirected for in-coupling.

[0071] The illustrated set 660 of stacked waveguides includes waveguides 670, 680, and 690. Each waveguide includes an associated incoupling optical element (which may also be referred to as the light input area on the waveguide), for example, incoupling optical element 700 is disposed on a major surface (e.g., the top major surface) of waveguide 670, incoupling optical element 710 is disposed on a major surface (e.g., the top major surface) of waveguide 680, and incoupling optical element 720 is disposed on a major surface (e.g., the top major surface) of waveguide 690. In some embodiments, one or more of the incoupling optical elements 700, 710, 720 may be disposed on a bottom major surface of an individual waveguide 670, 680, 690 (particularly if one or more of the incoupling optical elements is a reflective turning optical element). As shown, the incoupling optical elements 700, 710, 720 may be disposed on the upper major surfaces of the respective waveguides 670, 680, 690 (or on top of the next lower waveguide), particularly if the incoupling optical elements are transmissive deflecting optical elements. In some embodiments, the incoupling optical elements 700, 710, 720 may be disposed within the body of the respective waveguides 670, 680, 690. In some embodiments, as discussed herein, the incoupling optical elements 700, 710, 720 are wavelength selective, such that they selectively redirect one or more wavelengths of light while transmitting other wavelengths of light. Although illustrated on one side or corner of the respective waveguides 670, 680, 690, it should be understood that the incoupling optical elements 700, 710, 720 may be disposed within other areas of the respective waveguides 670, 680, 690 in some embodiments. As described herein, in some embodiments, the incoupling optical elements 700, 710, 720 may be integrated with surface portions of the waveguides 670, 680, 690.

[0072] As shown, the in-coupling optical elements 700, 710, 720 may be laterally offset from one another. In some embodiments, each in-coupling optical element may be offset to receive light without that light passing through another in-coupling optical element. For example, each in-coupling optical element 700, 710, 720 may be configured to receive light from different image input devices 360, 370, 380, 390, and 400 as shown in FIG. 6, and may be separated (e.g., laterally spaced) from the other in-coupling optical elements 700, 710, 720 so as to not substantially receive light from others of the in-coupling optical elements 700, 710, 720.

[0073] Each waveguide also includes an associated optically dispersive element, for example, optically dispersive element 730 is disposed on a major surface (e.g., a top major surface) of waveguide 670, optically dispersive element 740 is disposed on a major surface (e.g., a top major surface) of waveguide 680, and optically dispersive element 750 is disposed on a major surface (e.g., a top major surface) of waveguide 690. In some other embodiments, optically dispersive elements 730, 740, 750 may be disposed on the bottom major surfaces of associated waveguides 670, 680, 690, respectively. In some other embodiments, optically dispersive elements 730, 740, 750 may be disposed on both the top and bottom major surfaces of associated waveguides 670, 680, 690, respectively, or optically dispersive elements 730, 740, 750 may be disposed on different ones of the top and bottom major surfaces in different associated waveguides 670, 680, 690, respectively. As described herein, in some embodiments, the optically dispersive elements 730, 740, 750 may be integrated with surface portions of the waveguides 670, 680, 690.

[0074] The waveguides 670, 680, 690 may be spaced apart and separated, for example, by gas, liquid, and / or solid layers of material. For example, as shown, layer 760a may separate the waveguides 670 and 680, and layer 760b may separate the waveguides 680 and 690. In some embodiments, layers 760a and 760b are formed from a low index material (i.e., a material having a lower index of refraction than the material forming the immediately adjacent ones of the waveguides 670, 680, 690). Preferably, the index of refraction of the material forming layers 760a, 760b is 0.05 or more or 0.10 or less than the index of refraction of the material forming the waveguides 670, 680, 690. Advantageously, the lower refractive index layers 760a, 760b may act as cladding layers to promote total internal reflection (TIR) ​​of light through the waveguides 670, 680, 690 (e.g., TIR between the top and bottom major surfaces of each waveguide). In some embodiments, the layers 760a, 760b are formed from air. Although not shown, it should be understood that the top and bottom of the illustrated set of waveguides 660 may include adjacent cladding layers.

[0075] Preferably, for ease of manufacturing and other considerations, the materials forming the waveguides 670, 680, 690 are similar or the same, and the materials forming the layers 760a, 760b are similar or the same. In some embodiments, the materials forming the waveguides 670, 680, 690 may vary between one or more of the waveguides, and / or the materials forming the layers 760a, 760b may differ while still maintaining the various refractive index relationships described above.

[0076] 9A, light rays 770, 780, 790 are incident on the set of waveguides 660. It should be understood that light rays 770, 780, 790 may be injected into the waveguides 670, 680, 690 by one or more image injection devices 360, 370, 380, 390, 400 (FIG. 6).

[0077] In some embodiments, the light beams 770, 780, 790 have different properties, e.g., different wavelengths or different wavelength ranges, that may correspond to different colors. Each of the incoupling optical elements 700, 710, 720 deflects the incident light such that the light propagates through a respective one of the waveguides 670, 680, 690 by TIR. In some embodiments, each of the incoupling optical elements 700, 710, 720 selectively deflects one or more particular wavelengths of light while transmitting other wavelengths to the underlying waveguide and associated incoupling optical element.

[0078] For example, incoupling optical element 700 may be configured to deflect light beam 770 having a first wavelength or wavelength range while transmitting light beams 780 and 790 having different second and third wavelengths or wavelength ranges, respectively. The transmitted light beam 780 impinges on and is deflected by incoupling optical element 710, which is configured to deflect light of the second wavelength or wavelength range. Light beam 790 is deflected by incoupling optical element 720, which is configured to selectively deflect light of the third wavelength or wavelength range.

[0079] 9A, the deflected light rays 770, 780, 790 are deflected to propagate through the corresponding waveguides 670, 680, 690. That is, the incoupling optical element 700, 710, 720 of each waveguide deflects the light into its corresponding waveguide 670, 680, 690 and incouplings the light into the corresponding waveguide. The light rays 770, 780, 790 are deflected at an angle that causes the light to propagate through the respective waveguides 670, 680, 690 by TIR. The light rays 770, 780, 790 propagate through the respective waveguides 670, 680, 690 by TIR until they impinge on the corresponding optical dispersive element 730, 740, 750 of the waveguide.

[0080]

[0046] Referring now to Figure 9B, a perspective view of the multiple stacked waveguide embodiment of Figure 9A is illustrated. As described above, the in-coupled light rays 770, 780, 790 are deflected by the in-coupling optical elements 700, 710, 720, respectively, and then propagate by TIR within the waveguides 670, 680, 690, respectively. The light rays 770, 780, 790 then impinge on the optically dispersive elements 730, 740, 750, respectively. The optically dispersive elements 730, 740, 750 deflect the light rays 770, 780, 790 to propagate towards the out-coupling optical elements 800, 810, 820, respectively.

[0081] In some embodiments, the optically dispersive elements 730, 740, 750 are orthogonal pupil expanders (OPEs). In some embodiments, the OPEs deflect or disperse the light to the out-coupling optical elements 800, 810, 820, and in some embodiments may also increase the beam or spot size of this light as it propagates to the out-coupling optical elements. In some embodiments, the optically dispersive elements 730, 740, 750 may be omitted and the in-coupling optical elements 700, 710, 720 may be configured to deflect the light directly to the out-coupling optical elements 800, 810, 820. For example, referring to FIG. 9A, the optically dispersive elements 730, 740, 750 may be replaced with the out-coupling optical elements 800, 810, 820, respectively. In some embodiments, the outcoupling optical elements 800, 810, 820 are exit pupils (EPs) or exit pupil expanders (EPEs) that direct light into the viewer's eye 210 (FIG. 7). It should be understood that an OPE may be configured to increase the size of the eyebox in at least one axis, and an EPE may increase the eyebox in an axis that intersects, e.g., perpendicular to, the axis of the OPE. For example, each OPE may be configured to redirect a portion of the light striking the OPE to an EPE of the same waveguide, while allowing the remaining portion of the light to continue propagating down the waveguide. Again, in response to striking the OPE, another portion of the remaining light is redirected to the EPE, which continues to propagate further down the waveguide, and so on. Similarly, in response to striking the EPE, a portion of the impinging light is directed out of the waveguide towards the user, which continues to propagate through the waveguide until it again strikes the EP, at which point another portion of the impinging light is directed out of the waveguide, and so on. As a result, a single beam of internally coupled light may be "replicated" each time a portion of that light is redirected by an OPE or EPE, thereby forming a cloned beam field of light, as shown in Figure 6. In some embodiments, the OPE and / or EPE may be configured to modify the size of the beam of light.

[0082] Thus, referring to Figures 9A and 9B, in some embodiments, a set of waveguides 660 includes, for each primary color, a waveguide 670, 680, 690, an in-coupling optical element 700, 710, 720, an optical dispersion element (e.g., OPE) 730, 740, 750, and an out-coupling optical element (e.g., EP) 800, 810, 820. The waveguides 670, 680, 690 may be stacked with an air gap / cladding layer between each one. The in-coupling optical element 700, 710, 720 redirects or deflects the incoming light into its waveguide (with different in-coupling optical elements receiving different wavelengths of light). The light then propagates at an angle that will result in TIR within the individual waveguides 670, 680, 690. In the illustrated embodiment, light ray 770 (e.g., blue light) is deflected by the first in-coupling optical element 700 in the manner previously described, then continues to bounce back down the waveguide, interacting with the optically dispersive element (e.g., OPE) 730 and then the out-coupling optical element (e.g., EP) 800. Light rays 780 and 790 (e.g., green and red light, respectively) pass through the waveguide 670, where light ray 780 impinges on and is deflected by the in-coupling optical element 710. Light ray 780 will then proceed via TIR back down the waveguide 680, to its optically dispersive element (e.g., OPE) 740 and then the out-coupling optical element (e.g., EP) 810. Finally, light ray 790 (e.g., red light) passes through the waveguide 690 and impinges on the optically in-coupling optical element 720 of the waveguide 690. The light in-coupling optical element 720 deflects the light beam 790 such that it propagates by TIR to a light dispersive element (e.g., OPE) 750 and then by TIR to an out-coupling optical element (e.g., EP) 820. The out-coupling optical element 820 then finally out-couples the light beam 790 to a viewer, who also receives the out-coupled light from the other waveguides 670, 680.

[0083] FIG. 9C illustrates a top-down plan view of an example of the multiple stacked waveguides of FIGS. 9A and 9B. As shown, the waveguides 670, 680, 690 may be vertically aligned with each waveguide's associated light dispersive element 730, 740, 750 and associated out-coupling optical elements 800, 810, 820. However, as discussed herein, the in-coupling optical elements 700, 710, 720 are not vertically aligned. Rather, the in-coupling optical elements are preferably non-overlapping (e.g., laterally spaced apart, as seen in the top-down view). As discussed further herein, this non-overlapping spatial arrangement facilitates the injection of light from different sources into different waveguides on a one-to-one basis, thereby allowing a specific light source to be uniquely coupled to a specific waveguide. In some embodiments, an arrangement including non-overlapping spatially separated in-coupling optical elements may be referred to as a shifted pupil system, and the in-coupling optical elements in these arrangements may correspond to sub-pupils.

[0084] 9D illustrates an example of a wearable display system 60 into which the various waveguide and associated systems disclosed herein may be integrated. In some embodiments, the display system 60 is the system 250 of FIG. 6, which diagrammatically illustrates some portions of the system 60 in greater detail. For example, the waveguide assembly 260 of FIG. 6 may be part of the display 70.

[0085] 9D, the display system 60 includes a display 70 and various mechanical and electronic modules and systems to support the functionality of the display 70. The display 70 may be coupled to a frame 80 that is wearable by a display system user or viewer 90 and configured to position the display 70 in front of the eye of the user 90. The display 70 may be considered an eyepiece in some embodiments. In some embodiments, a speaker 100 is coupled to the frame 80 and configured to be positioned adjacent to the ear canal of the user 90 (in some embodiments, another speaker, not shown, may also be optionally positioned adjacent the other ear canal of the user to provide stereo / shapeable sound control). The display system 60 may also include one or more microphones 110 or other devices to detect sound. In some embodiments, the microphones may be configured to allow the user to provide input or commands (e.g., voice menu command selections, natural language questions, etc.) to the system 60 and / or enable audio communication with other persons (e.g., other users of a similar display system). The microphone may further be configured as an ambient sensor to collect audio data (e.g., sounds from the user and / or the environment). In some embodiments, the display system 60 may further include one or more outwardly directed environmental sensors 112 configured to detect objects, stimuli, people, animals, places, or other aspects of the world around the user. For example, the environmental sensors 112 may include one or more cameras, which may be positioned, for example, facing outward, to capture images similar to at least a portion of the user 90's normal field of view. In some embodiments, the display system may also include an ambient sensor 120a, which may be separate from the frame 80 and attached to the body of the user 90 (e.g., on the user 90's head, torso, limbs, etc.). The ambient sensor 120a may, in some embodiments, be configured to obtain data characterizing a physiological state of the user 90. For example, the sensor 120a may be an electrode.

[0086] 9D, the display 70 is operably coupled by a communication link 130, such as wired leads or wireless connectivity, to a local data processing module 140, which may be mounted in a variety of configurations, such as fixedly attached to the frame 80, fixedly attached to a helmet or hat worn by the user, built into headphones, or otherwise removably attached to the user 90 (e.g., in a backpack configuration, in a belt-connected configuration). Similarly, the sensor 120a may be operably coupled to the local processor and data module 140 by a communication link 120b, such as wired leads or wireless connectivity. The local processing and data module 140 may comprise a hardware processor and digital memory, such as non-volatile memory (e.g., flash memory or hard disk drive), both of which may be utilized to aid in processing, caching, and storing data. Optionally, the local processor and data module 140 may include one or more central processing units (CPUs), graphics processing units (GPUs), dedicated processing hardware, and the like. The data may include a) data captured from sensors (e.g., which may be operatively coupled to the frame 80 or otherwise attached to the user 90), such as image capture devices (such as cameras), microphones, inertial measurement units, accelerometers, compasses, GPS units, wireless devices, gyroscopes, and / or other sensors disclosed herein, and / or b) data obtained and / or processed using the remote processing module 150 and / or remote data repository 160 (including data related to virtual content), possibly for passing to the display 70 after processing or retrieval. The local processing and data module 140 may be operatively coupled to the remote processing module 150 and the remote data repository 160 by communication links 170, 180, such as via wired or wireless communication links, such that these remote modules 150, 160 are operatively coupled to each other and available as resources to the local processing and data module 140.In some embodiments, local processing and data module 140 may include one or more of an image capture device, a microphone, an inertial measurement unit, an accelerometer, a compass, a GPS unit, a wireless device, and / or a gyroscope. In some other embodiments, one or more of these sensors may be mounted to frame 80 or may be a stand-alone structure that communicates with local processing and data module 140 by a wired or wireless communication path.

[0087] 9D , in some embodiments, remote processing module 150 may comprise one or more processors configured to analyze and process data and / or image information, including, for example, one or more central processing units (CPUs), graphics processing units (GPUs), dedicated processing hardware, etc. In some embodiments, remote data repository 160 may comprise digital data storage facilities that may be available through the Internet or other networking configurations in a "cloud" resource configuration. In some embodiments, remote data repository 160 may include one or more remote servers that provide information, for example, information for generating augmented reality content to local processing and data module 140 and / or remote processing module 150. In some embodiments, all data is stored and all calculations are performed within the local processing and data module, allowing for fully autonomous use from the remote modules. Optionally, an external system (e.g., one or more processors, one or more computer systems), including a CPU, GPU, etc., may perform at least a portion of the processing (e.g., generating image information, processing data) and provide information to and receive information from modules 140, 150, 160, e.g., via a wireless or wired connection. (Example Waveguide)

[0088] As described with respect to FIG. 6 , light containing image information can be provided by light projector system 520 (e.g., by image input devices 360, 370, 380, 390, 400 of projector system 520) to an eyepiece (e.g., an eyepiece comprising waveguide assembly 260 comprising waveguides 270, 280, 290, 300, 310). Low coupling efficiency of light between projector system 520 and waveguides 270, 280, 290, 300, 310 can reduce the total efficiency of waveguide assembly 260 and degrade the overall image quality provided to a viewer. Compared to waveguides used in current display systems, certain implementations of the waveguides described herein can advantageously provide higher coupling efficiency, better image quality, and / or simpler manufacturing processes.

[0089] 10, an example waveguide with an integrated in-coupling optical element is illustrated. The example waveguide 1000 includes an integrated in-coupling optical element 1030 configured to couple incident light into the waveguide 1000. The light can propagate through the waveguide 1000 via total internal reflection. One or more optically dispersive elements 1035 can extract the light and direct it towards one or more out-coupling optical elements 1040, which can direct it out of the waveguide 1000 and into the eye of a viewer.

[0090] In various implementations, the waveguide 1000 can include a layer 1005 that includes a substantially optically transparent material. In some implementations, the layer 1005 can be highly transparent to wavelengths of light in the visible spectrum, e.g., 390-700 nm. For example, the layer 1005 can transmit about 85% to about 100%, about 90% to about 100%, about 95% to about 100%, about 96% to about 100%, about 97% to about 100%, or about 98% to about 100% of light in the visible light spectrum across its thickness. In some cases, the layer 1005 can be formed from a polymeric material, such as optical polymers and / or transparent polymers used in ophthalmic lenses. Some exemplary polymers that may be used include thiol-based polymers, MR series polymers available from Mitsui Chemicals America, Inc. (Rye Brook, New York), LPB or LPL series polymers available from Mitsubishi Chemical Corporation (Tokyo, Japan), or OrmoStamp available from micro resist technology GmbH (Berlin, Germany). In some cases, layer 1005 may be formed from a combination of materials, such as a first layer of a first material and a second layer of a second material. Other implementations are possible.

[0091] 10, the layer 1005 can have a first major surface 1010 and a second major surface 1020. The first and second major surfaces 1010, 1020 can be configured such that light containing image information can propagate through and be guided within the layer 1005. For example, light can be guided through the layer 1005 by reflecting off the first major surface 1010 and the second major surface 1020 via total internal reflection from the surfaces. In various implementations, the first and second major surfaces 1010, 1020 can have a relatively low surface roughness. For example, in some implementations, the surface roughness is within the range of about 0.05 nm to about 3.0 nm (about 0.05 nm, about 0.07 nm, about 0.1 nm, about 0.5 nm, about 1.0 nm, about 1.5 nm, about 2.0 nm, about 2.5 nm, about 3.0 nm, etc.), any range within this range (about 0.05 nm to about 2.5 nm, about 0.07 nm to about 2.5 nm, about 0.1 nm to about 2.5 nm, about 0.5 nm, etc.). The roughness of the waveguide may be, for example, about 0.05 nm to about 2.0 nm, about 0.07 nm to about 2.0 nm, about 0.1 nm to about 2.0 nm, about 0.5 nm to about 2.0 nm, about 0.7 nm to about 2.0 nm, about 1.0 nm to about 2.0 nm, etc.), any value within these ranges, or any range formed by such values. Without being bound by theory, a waveguide with a relatively low surface roughness can preserve imaging quality. Thus, in various implementations, the first and second major surfaces 1010, 1020 can have a relatively low surface roughness such that the layer 1005 can preserve image information and preserve imaging.

[0092] In various implementations, the first major surface 1010 can include a first smaller surface portion 1011 and a second larger surface portion 1012 that are monolithically integrated with the layer 1005 and each other 1011, 1012. In some cases, the first smaller surface portion 1011 can include at least a portion of the incoupling optical element 1030. For example, the first smaller surface portion 1011 can form at least a portion of the incoupling optical element 1030. In various implementations, the first smaller surface portion 1011 can be integrated with the incoupling optical element 1030 such that the incoupling optical element 1030 can be configured to efficiently couple light incident on the incoupling optical element 1030 into the layer 1005. As described herein, light may propagate through layer 1005 by total internal reflection from second major surface 1020 and second, larger surface portion 1012 of first major surface 1010 .

[0093] In some implementations, the internal coupling optical element 1030 can be configured to deflect light containing image information within the layer 1005 of the waveguide 1000. In FIG. 10, the internal coupling optical element 1030 comprises a tilted surface portion (e.g., a first smaller surface portion 1011). For example, the tilted surface portion can comprise the first smaller surface portion 1011 of the first major surface 1010 that is tilted relative to the second larger surface portion 1012 of the first major surface 1010 and the second major surface 1020. The tilted surface portion 1011 can be tilted within a range of about 30 degrees to about 60 degrees (about 30 degrees, about 35 degrees, about 40 degrees, about 45 degrees, about 50 degrees, about 55 degrees, about 60 degrees, etc.) relative to a plane parallel to the first major surface 1010 and / or the second major surface 1020, any range within this range (about 30 degrees to about 50 degrees, about 35 degrees to about 50 degrees, about 40 degrees to about 50 degrees, about 30 degrees to about 55 degrees, about 40 degrees to about 55 degrees, etc.), any value within these ranges, or any range formed by such values. In some embodiments, the angle of tilt can be based, at least in part, on the thickness T of the layer 1005 of the waveguide 1000.

[0094] In some implementations, the tilted surface portion 1011 can form a portion of a depression (or facet) 1050 in the layer 1005. With continued reference to FIG. 10, the depression 1050 can have a depth D (or height) and a width W. In some implementations, the depth D of the depression 1050 can be less than the thickness T of the layer 1005. In some cases, the depth D of the depression 1050 can be at least half the thickness T, or at least three-quarters the thickness T of the layer 1005. For example, the depression 1050 can have a depth D of about 0.5T, about 0.6T, about 0.75T, about 0.8T, about 0.9T, etc., or within any range formed by such values. Other values ​​and ranges are also possible. In some implementations, the depression 1050 can have a depth D substantially equal to the thickness T of the layer 1005.

[0095] In some cases, the depth D of the depression 1050 can be within a range of about 50 microns to about 550 microns (about 50 microns, about 75 microns, about 100 microns, about 150 microns, about 200 microns, about 250 microns, about 300 microns, about 350 microns, about 400 microns, about 450 microns, about 500 microns, about 550 microns, etc.), any range within this range (about 50 microns to about 500 microns, about 75 microns to about 500 microns, about 100 microns to about 500 microns, about 75 microns to about 550 microns, about 100 microns to about 550 microns, about 150 microns to about 550 microns, etc.), any value within these ranges, or any range formed by such values. In some cases, the depth D of the depression 1050 can be outside of these ranges.

[0096] In some cases, the width W of the recess 1050 can be within a range of about 25 microns to about 350 microns (about 30 microns, about 40 microns, about 50 microns, about 75 microns, about 100 microns, about 150 microns, about 200 microns, about 250 microns, about 300 microns, about 350 microns, etc.), any range within this range (about 25 microns to about 300 microns, about 50 microns to about 300 microns, about 75 microns to about 300 microns, about 30 microns to about 350 microns, about 40 microns to about 350 microns, about 50 microns to about 350 microns, about 75 microns to about 350 microns, etc.), any value within these ranges, or any range formed by such values. In some cases, the width W of the recess 1050 can be outside these ranges.

[0097] In some implementations, the recess 1050 can comprise air. Alternatively, the recess 1050 can comprise the same material as the layer 1005 or another substantially optically transparent material (e.g., a material with a substantially similar refractive index). In some such implementations, the recess 1050 can form at least a portion of a prism (e.g., a triangular prism) having a depth D and a width W as described herein, with the tilted surface portion 1011 forming one of the surfaces of the prism. Thus, some implementations of the waveguide can include an integrated internal coupling optical element 1030 in the form of a prism. In various implementations, the prism can be configured to reflect light containing image information within the layer 1005 of the waveguide 1000. For example, in some implementations, the prism can be configured to reflect light by total internal reflection when the light strikes the surface of the prism at an angle greater than the critical angle.

[0098] Conventional gratings used as internal coupling elements can potentially result in non-uniform brightness of the image due to different diffraction efficiencies versus input angle. Advantageously, in various implementations, the internal coupling optical element 1030 with a prism can achieve a more uniform reflectance (in some cases, very uniform reflectance) versus input angle, thus improving the brightness uniformity of the display output image. In addition, in certain implementations described herein, the internal coupling optical element 1030 with an integrated prism of the same material (or material with a substantially similar refractive index) as the waveguide can achieve a near perfect index match (or a substantially similar index match) with the waveguide without an interface (e.g., a rough surface) between the prism and the waveguide material. In some such implementations, the internal coupling optical element 1030 can reduce back reflections into the projector (in some cases, achieve very low back reflections), thus reducing image persistence artifacts (in some cases, no persistence). Additionally, the internal coupling optical element 1030, comprising a prism integrated with the surface 1011 of the waveguide 1000, can allow direct contact with the waveguide 1000 leading to increased internal coupling between the light projector and the waveguide 1000, and can simplify the manufacturing process by simplifying and / or eliminating alignment steps between the prism and the waveguide during assembly.

[0099] 11 illustrates another example waveguide with an integrated in-coupling optical element. The example waveguide 1100 is similar to the example waveguide 1000 of FIG. 10 (e.g., first major surface 1110, second major surface 1120, layer 1105, recess 1150, one or more optically dispersive elements 1135, one or more out-coupling optical elements 1140, etc.), except that the tilted surface portion 1111 may form at least a portion of a turning mirror. For example, in some implementations, the in-coupling optical element 1130 may include a layer 1145 of reflective material (e.g., metallization) disposed on the tilted surface portion 1111. In some cases, the reflective layer 1145 may include a metal film (e.g., Au, Al, Ag, or any reflective metal). The thickness of the metal film can be in the range of about 5 nm to about 500 nm (about 5 nm, about 10 nm, about 20 nm, about 30 nm, about 40 nm, about 50 nm, about 75 nm, about 100 nm, about 150 nm, about 200 nm, about 250 nm, about 300 nm, about 350 nm, about 400 nm, about 450 nm, about 500 nm, etc.), any range within this range (about 5 nm to about 400 nm, about 5 nm to about 450 nm, about 10 nm to about 400 nm, about 10 nm to about 450 nm, about 5 nm to about 500 nm, about 10 nm to about 500 nm, about 50 nm to about 500 nm, about 100 nm to about 500 nm, etc.), any value within these ranges, or any range formed by such values. In some implementations, the recess 1150 may be filled with a reflective material or filler. An incoupling optical element 1130 comprising a turning mirror (e.g., a tilted surface portion that is metalized) can be configured to reflect light containing image information within layer 1105 of waveguide 1100. An incoupling optical element 1130 comprising a turning mirror integrated with a surface of waveguide 1100 can allow direct contact with waveguide 1100 leading to increased incoupling between the light projector and the waveguide, and can simplify the manufacturing process by simplifying and / or eliminating alignment steps between the turning mirror and the waveguide during assembly.

[0100] In some implementations, the tilted surface portion 1111 may extend completely through the thickness of the waveguide layer 1105, such that the tilted surface portion 1111 is an edge (e.g., a surface extending between major surfaces) of the waveguide layer 1105 instead of a portion of the first major surface 1110. In other words, in some implementations, the internal coupling optical element 1130 can be integrated with an edge of the waveguide layer 1105 instead of the major surface 1110.

[0101] FIG. 12 illustrates another example waveguide with an integrated in-coupling optical element. The example waveguide 1200 is similar to the example waveguide 1100 of FIG. 11 (e.g., first major surface 1210, second major surface 1220, layer 1205, recess 1250, one or more optically dispersive elements 1235, one or more out-coupling optical elements 1240, etc.), except that the in-coupling optical element 1230 has a curvature at its tilted surface portion 1211. For example, in the in-coupling optical element 1230 illustrated in FIG. 12, the first smaller surface portion 1211 of the first major surface 1210 is curved relative to the second larger surface portion 1212 of the first major surface 1210 and the second major surface 1220. As another example, the curved surface portion 1211 may be an edge portion of the waveguide 1205.

[0102] In various implementations, the internal coupling optical element 1230, comprising a turning mirror (e.g., a metallized curved surface portion), can be configured to reflect light containing image information within the layer 1205 of the waveguide 1200. In some implementations, the curved surface portion 1211 can be configured to provide optical power (e.g., a turning mirror with optical power). In some implementations, the curved surface portion 1211 can complement the optical power of other components (e.g., complement the optical power of an exit pupil expander) and / or make the optical power of other components unnecessary. In some examples, the curved surface portion 1211 can be configured to provide positive optical power. In some such implementations, the tilted surface portion 1211 can have a concave curvature from the perspective of most locations within the substantially optically transparent layer 1205. As another example, the curved surface portion 1211 can be configured to provide negative optical power. In some such implementations, the tilted surface portion 1211 can have a convex curvature from the perspective of most locations within the layer 1205 .

[0103] FIG. 13 illustrates another example waveguide with an integrated in-coupling optical element. In the example waveguide 1300, the curved surface portion 1311 can form at least a portion of the lens 1351 (e.g., spherical, cylindrical, parabolic, freeform lens, etc.) of the integrated prism 1352 and lens 1351. In the in-coupling optical element 1330 illustrated in FIG. 13, the first smaller surface portion 1311 of the first major surface 1310 is curved relative to the second larger surface portion 1312 of the first major surface 1310 and the second major surface 1320. In some implementations, the curved surface portion 1311 can be convex as seen from most of the waveguide 1305. In some examples, the curved surface portion 1311 can form a lens with positive optical power. In some implementations, the curved surface portion 1311 can be concave as seen from most of the waveguide 1305. In some implementations, the curved surface portion 1311 can form a negative power lens. In various implementations, the integrated prism 1352 and lens 1351 can be configured to direct light containing image information within the layer 1305 of the waveguide 1300. For example, in some implementations, the prism 1352 can be configured to reflect light by total internal reflection when the light strikes a surface of the prism 1352 at an angle greater than a critical angle, and the lens 1351 can be configured to focus and / or refract the light into the layer 1305. Forming at least a portion of the lens 1351 with the surface 1311 of the waveguide 1300 can improve light coupling between a light projector and the waveguide and can simplify assembly by eliminating an alignment step between the lens and the waveguide.

[0104] FIG. 14 illustrates another example waveguide with at least a portion of a lens 1460 integrated with the waveguide 1400. In the example illustrated in FIG. 14, the entire lens 1460 is monolithically integrated with the waveguide 1400. Although the lens 1460 is illustrated as being integrated with the major surface 1420 of the waveguide layer 1405, in some implementations the lens 1460 can be integrated with the edge of the waveguide layer. In addition to improving light coupling and simplifying assembly, monolithically integrating the lens with the waveguide can reduce the total footprint (e.g., size and / or weight) of the waveguide display device by eliminating lens components in the projector and / or between the projector and the waveguide. In some implementations, the lens 1460 can be comprised of a spherical, cylindrical, parabolic, freeform lens. Any shape is also possible. In some cases, the lens 1460 can be a convex lens. In some embodiments, the lens 1460 can provide positive refractive power. In some implementations, the lens 1460 can be a concave lens. In some embodiments, the lens 1460 can provide negative refractive power.

[0105] In some implementations, the lens 1460 can be aligned with another in-coupling optical element. For example, as illustrated in FIG. 15, the in-coupling optical element 1530 can be configured to turn the light into the layer 1505 after passing through the lens 1560. In some cases, the in-coupling optical element 1530 can be disposed on a surface 1510 of the layer 1505 opposite the surface 1520 on which the lens 1560 is disposed. In some other cases, the in-coupling optical element 1530 can be disposed on a surface adjacent to the surface on which the lens is disposed. In some other cases, the in-coupling optical element 1530 can be disposed on the same surface on which the lens is disposed. In some implementations, the in-coupling optical element 1530 can be integrated with a surface of the waveguide 1500. For example, the in-coupling optical element 1530 can include any of the in-coupling optical elements described herein (e.g., an integrated facet, a prism, a turning mirror, a lens, or a combination thereof).

[0106] As another example, the internal coupling optical element 1530 can include an integrated grating. For example, in some implementations, the first smaller surface portion 1511 of the first major surface 1510 can form at least a portion of the grating (e.g., the first smaller surface portion 1511 can include an undulating surface relief). The grating can be a reflective grating. In some cases, the linewidth of the grating can be within the range of about 25 nm to about 550 nm (about 25 nm, about 50 nm, about 60 nm, about 70 nm, about 75 nm, about 100 nm, about 150 nm, about 200 nm, about 250 nm, about 300 nm, about 350 nm, about 400 nm, about 450 nm, about 500 nm, about 550 nm, etc.), any range within this range (about 25 nm to about 400 nm, about 50 nm to about 400 nm, about 25 nm to about 450 nm, about 50 nm to about 450 nm, about 25 nm to about 500 nm, about 50 nm to about 500 nm, about 75 nm to about 500 nm, about 100 nm to about 500 nm, about 50 nm to about 550 nm, about 75 nm to about 550 nm, etc.), any value within these ranges, or any range formed by such values. Other implementations are possible.

[0107] In some cases, the pitch of the grating can be between about 150 microns and about 650 microns (about 150 microns, about 200 microns, about 250 microns, about 300 microns, about 350 microns, about 400 microns, about 450 microns, about 500 microns, about 550 microns, about 600 microns, about 650 microns, etc.), any range within this range (about 150 microns to about 500 microns, about 150 microns to about 550 microns, about 150 microns to about 600 microns, about 200 microns to about 500 microns, about 200 microns to about 550 microns, about 200 microns to about 600 microns, etc.), any value within these ranges, or any range formed by such values. Other embodiments are possible.

[0108] Other examples of the in-coupling optical element can be integrated with the surface of the waveguide. Additionally, although various implementations are described herein as in-coupling optical elements, other optical elements can also be integrated with the surface of the waveguide. For example, the optically dispersive element 1035, 1135, 1235, 1335, 1435, 1535, and / or the out-coupling optical element 1040, 1140, 1240, 1340, 1440, 1540 can be integrated with the surface of the waveguide. Additionally, although various implementations of the optically dispersive element 1035, 1135, 1235, 1335, 1435, 1535, and / or the out-coupling optical element 1040, 1140, 1240, 1340, 1440, 1540 are illustrated as gratings, the optically dispersive element and / or the out-coupling optical element can be any of the integrated optical elements described herein.

[0109] Some implementations may include one or more anti-reflection structures to reduce reflections when a viewer is viewing through the waveguide. For example, as shown in FIG. 16, an anti-reflection structure 1665 is provided adjacent to the in-coupling optical element 1630. One or more anti-reflection structures 1665 can also be provided adjacent to and / or opposite the out-coupling optical element 1640 (or light dispersive element). One or more anti-reflection structures 1665 can be provided on any surface portion of the waveguide 1600. In FIG. 16, the in-coupling optical element 1630 and the out-coupling optical element 1640 are illustrated as gratings integrated with the surface 1620 of the waveguide 1600 (e.g., similar to the grating 1530 shown in FIG. 15). In various implementations, the optical elements (e.g., the in-coupling optical element, the out-coupling optical element, and / or the light dispersive element) may be any of the integrated optical elements described herein.

[0110] With conventional anti-reflective coatings, multiple layers of coatings are typically provided, and it can be difficult to surround the grating with such layers. Furthermore, there is generally a cost associated with providing each additional layer of conventional anti-reflective coatings. In various implementations, at least a portion of the anti-reflective structure can also be integrated with the surface of the waveguide (and in some implementations can surround the grating). For example, surface portion 1621 of waveguide 1600 can form at least a portion of anti-reflective structure 1665. In some implementations, anti-reflective structure 1665 can include a surface relief pattern. For example, anti-reflective structure 1665 can comprise an undulating pattern. In some implementations, the undulating pattern can be undulating in one dimension or one direction. In some implementations, the undulating pattern can be undulating in two dimensions or two directions. The undulating pattern can include a periodic pattern. For example, the period of the pattern can be in the range of about 25 nm to about 250 nm (about 25 nm, about 50 nm, about 75 nm, about 100 nm, about 125 nm, about 150 nm, about 175 nm, about 200 nm, about 250 nm, etc.), any range within this range (about 25 nm to about 200 nm, about 50 nm to about 200 nm, about 75 nm to about 200 nm, about 100 nm to about 200 nm, about 50 nm to about 250 nm, about 75 nm to about 250 nm, about 100 nm to about 250 nm, etc.), any value within these ranges, or any range formed by such values. In some implementations, the pitch of the antireflective structures 1665 can be such that the antireflective structures 1665 are not diffractive to visible light. Other implementations are possible.

[0111] In some cases, the height of the pattern can be in the range of about 5 nm to about 250 nm (about 5 nm, about 10 nm, about 20 nm, about 30 nm, about 50 nm, about 75 nm, about 100 nm, about 125 nm, about 150 nm, about 175 nm, about 200 nm, about 250 nm, etc.), any range within this range (about 5 nm to about 200 nm, about 10 nm to about 200 nm, about 50 nm to about 200 nm, about 10 nm to about 250 nm, about 50 nm to about 250 nm, about 75 nm to about 250 nm, about 100 nm to about 250 nm, etc.), any value within these ranges, or any range formed by such values. Other embodiments are possible.

[0112] FIG. 16A shows a magnified image of an exemplary anti-reflection structure adjacent to an internal coupling optical element. FIG. 16B shows a magnified image of an exemplary anti-reflection structure. As shown in these figures, nanostructures can be integrated with the surface of the waveguide. In various implementations, the extremely small size can have an effective refractive index with air so that the structure can act similarly to an anti-reflection coating. Anti-reflection structures integrated into the surface portion of the waveguide can be advantageously selectively provided on desired portions of the waveguide. For example, one or more anti-reflection structures can be provided to surround the internal coupling grating.

[0113] In some implementations, the anti-reflective structure can include a material disposed on the surface relief pattern. For example, in some examples, the material can have a desired refractive index. In some implementations, the anti-reflective structure can reduce (and / or in some cases minimize) reflections of images generated by adjacent waveguides. In some implementations, the anti-reflective structure can reduce (and / or in some cases minimize) phase delay as light impinges on the surface.

[0114] The anti-reflection structure can be optically aligned with the optical element. In some cases, the anti-reflection structure can be optically aligned with the optical element associated with another waveguide. For example, the anti-reflection structure 1665 can be configured to facilitate the passage of light through the waveguide 1600 to another waveguide. With reference to FIG. 9A, various implementations may include a stack 660 of waveguides 670, 680, 690. As illustrated in FIG. 9A, the internal coupling optical elements 700, 710, 720 can be laterally offset from each other such that each internal coupling optical element 700, 710, 720 can receive light without the light passing through another internal coupling optical element 700, 710, 720. In addition, the anti-reflection structure can be optically aligned with the internal coupling optical element associated with another waveguide. For example, an anti-reflection structure (e.g., 1665 shown in FIG. 16) can be positioned on the waveguide 670 above the in-coupling optical element (e.g., 710 in FIG. 9A) for the waveguide 680 such that the light 780 can transmit through the anti-reflection structure and the waveguide 670 and enter the in-coupling optical element 710 for coupling into the waveguide 680. As another example, the anti-reflection structure can be configured to reduce (and / or in some cases minimize) reflections from the light that is out-coupled from the waveguide and directed to the user. In some implementations, the anti-reflection structure can be optically matched with the out-coupling optical element and / or the optical dispersive element. With reference to FIG. 9A, the anti-reflection structure can be positioned on the side of the waveguide 670 closest to the waveguide 680 because the light that is out-coupled by the waveguide 680 passes through the waveguide 670. Other examples are possible.

[0115] As described herein, various implementations can include integrated optical elements. For example, some implementations can include surface portions that form at least a portion of an optical element (e.g., an in-coupling optical element, a light dispersing element, an out-coupling optical element, an anti-reflection structure, etc.). In some implementations, at least a portion of the optical element can be formed when forming the surface of the waveguide. As an example, some implementations can be molded such that at least a portion of the optical element can be formed into the surface of the waveguide. For example, with reference to FIG. 16, some implementations can include a waveguide comprising a molded layer 1605 of a substantially optically transparent material. The surface portions 1621, 1622 can be monolithically integrated with the molded layer 1605 and each other 1621, 1622. One of the surface portions 1621 can include at least a portion of a molded optical element 1630. In some examples, the layer 1605, the surfaces 1610, 1620, and the surface relief pattern 1665 can form a molded optical system. The waveguides 1000, 1100, 1200, 1300, 1400, 1500 in Figures 10-15 can also be molded. In some embodiments, the layers (e.g., 1005, 1105, 1205, 1305, 1405, 1505), the first surfaces (e.g., 1010, 1110, 1210, 1310, 1410, 1510), the second surfaces (e.g., 1020, 1120, 1220, 1320, 1420, 1520), and at least a portion of the optical elements (e.g., tilted surface portions 1011, 1111, curved surface portions 1211, 1311, lenses 1460, 1560, grating 1530) can form a single molded optical system.

[0116] Any of the waveguides 1000, 1100, 1200, 1300, 1400, 1500, 1600, or combinations thereof may be utilized as one of the waveguides of the waveguide stack 260 (FIG. 6) or 660 (FIGS. 9A-9C), for example, as one of the waveguides 270, 280, 290, 300, or 310 (FIG. 6), or 670, 680, or 690 (FIGS. 9A-9C). In addition, any of the optical elements described herein may be provided on any of the waveguides. For example, any of the optical elements 1030, 1130, 1230, 1330, 1460, 1530, 1560, 1630 may correspond to any of the in-coupling optical elements 700, 710, or 720 (FIGS. 9A-9C), the light dispersive elements 730, 740, or 750, and / or the out-coupling optical elements 570, 580, 590, 600, or 610 (FIG. 6), or 800, 810, or 820 (FIGS. 9A-9C). As another example, any of the optical elements 1030, 1130, 1230, 1330, 1460, 1530, 1560, 1630 may correspond to any of the features (e.g., lenses) 320, 330, 340, 350, 360, or 620 (FIG. 6). In some implementations, one or more anti-reflection structures 1665 may be provided on any of the waveguides 270, 280, 290, 300, or 310 (FIG. 6), or 670, 680, or 690 (FIGS. 9A-9C). Additionally, although some implementations have described the optical elements 1030, 1130, 1230, 1330, 1460, 1530, 1560, 1630, 1665 as being integrated with the major surfaces of the waveguide, any of the optical elements 1030, 1130, 1230, 1330, 1460, 1530, 1560, 1630, 1665 can be integrated with the edges of the waveguide (e.g., surfaces extending between the major surfaces). Exemplary Methods of Making a Waveguide

[0117] As described herein, at least a portion of the optical elements (e.g., at least a portion of the in-coupling optical elements, light dispersive elements, out-coupling optical elements, anti-reflection structures, etc.) may be integrated with the waveguide layer. As described herein, at least a portion of the waveguide surface can form at least a portion of the optical elements, which may simplify the manufacture of the waveguide and devices / systems incorporating the waveguide (e.g., fewer steps and / or fewer alignment issues, if any). By forming at least a portion of the optical elements with a surface portion of the waveguide, at least a portion of the optical elements can be perfectly index matched with the waveguide layer without an interface therebetween. Furthermore, in some implementations, by forming at least a portion of the optical elements with a surface portion of the waveguide, the optical elements can be formed on selective portions of the waveguide.

[0118] In various implementations, the waveguide layer (e.g., 1005, 1205, 1305, 1405, 1505, 1605) may be formed using a flowable material. At least a portion of the optical elements may be integrated with the waveguide layer by imprinting, followed by hardening or curing of the imprinted material. As an exemplary method, the waveguides may be formed by molding as described herein. Other types of molding, such as injection molding, may also be used. Inkjet, lithography, and / or nanoimprinting may also be used in some implementations, for example, to include optical elements such as lenses and / or prisms. In various implementations, the method may be used to form various shapes and sizes (e.g., macro-, micro-, and / or nano-sized features) and to form well-aligned features. Some implementations may also achieve a relatively flat surface (e.g., low surface roughness) without additional post-processing steps (e.g., without polishing). Moreover, some implementations can be repeated and relatively inexpensively implemented (eg, using inexpensive materials, equipment, and operations).

[0119] 17A-17D illustrate an exemplary method of forming a waveguide with integrated optical elements. Referring to FIG. 17A, a pair of molds 2001, 2002 are provided that are configured to face each other. At least one of the molds 2001, 2002 can include an imprint 2011, 2012 of at least a portion of an optical element. The imprint 2011, 2012 may be a negative of a desired portion of the optical element to be defined in the waveguide layer to be formed. For simplicity, the molds 2001, 2002 are illustrated as having a pattern of raised features to form, for example, one or more integrated gratings and / or anti-reflective structures as described herein. In some other implementations, the imprint may be a negative of at least a portion of a prism, a lens, an integrated prism and lens, and / or a turning mirror (tilted and / or curved) as described herein. It should be understood that imprints may be provided on molds 2001, 2002 to form any optical element, any combination of optical elements, and / or any additional structures, as desired. With continued reference to FIG. 17A, a mass of material 2003 for forming a waveguide layer may be deposited on mold 2001 (e.g., between molds 2001, 2002). As described herein, material 2003 may be a flowable material. For example, material 2003 may be a polymer (e.g., a resin).

[0120] 17B, ​​dies 2001, 2002 can be brought together to compress material 2003, thereby forming a waveguide layer. For example, dies 2001, 2001 can be brought into contact with material 2003 such that at least one of dies 2001, 2002 transfers a corresponding imprint into material 2003.

[0121] 17C, the compressed material 2003 may undergo a hardening process. As an example, the compressed material 2003 may undergo a curing process (e.g., exposure to ultraviolet light) to harden the material and form a substantially solid waveguide layer 2005. As shown, the negative pattern imprints 2011, 2012 can define at least a portion of the optical elements in the waveguide layer 2005.

[0122] 17D, the molds 2001, 2002 can be moved away from each other and the waveguide layer 2005 can be released from the molds 2001, 2002, thereby forming the waveguide 2000 such that the surface portion of the waveguide forms at least a portion of the optical element. In some implementations, additional steps can be performed, such as depositing material over the formed portion of the optical element and fabricating the remaining portion of the optical element. For example, the tilted surface portion (e.g., 1130 in FIG. 11) or the curved surface portion (e.g., 1230 in FIG. 12) can be metallized. As another example, material can be deposited on a surface relief pattern (e.g., 1665 in FIG. 16).

[0123] In the foregoing specification, the invention has been described with reference to specific embodiments thereof. It will, however, be apparent that various modifications and changes can be made therein without departing from the broader spirit and scope of the invention. The specification and drawings are, therefore, to be regarded in an illustrative rather than a restrictive sense.

[0124] Indeed, it should be understood that the systems and methods of the present disclosure each have several innovative aspects, none of which is solely responsible for or required for the desirable attributes disclosed herein. The various features and processes described above may be used independently of one another or may be combined in various ways. All possible combinations and subcombinations are intended to fall within the scope of the present disclosure.

[0125] Certain features described herein in the context of separate embodiments may also be implemented in combination in a single embodiment. Conversely, various features described in the context of a single embodiment may also be implemented in multiple embodiments separately or in any suitable subcombination. Furthermore, although features may be described above as acting in a combination and may even be initially claimed as such, one or more features from the claimed combination may, in some cases, be deleted from the combination, and the claimed combination may be directed to a subcombination or variation of the subcombination. No single feature or group of features is required or essential to every embodiment.

[0126] In particular, conditional statements used herein, such as "can," "could," "might," "may," "eg," and the like, unless specifically stated otherwise or understood otherwise within the context as used, are intended to generally convey that certain embodiments include certain features, elements, and / or steps, while other embodiments do not include them. Thus, such conditional statements are not intended to generally agree that features, elements, and / or steps are in any way required for one or more embodiments, or that one or more embodiments necessarily include logic for determining whether those features, elements, and / or steps should be included or performed in any particular embodiment, with or without authorial input or prompting. The terms "comprising," "including," "having," and the like, are synonymous and used inclusively in a non-limiting manner and do not exclude additional elements, features, acts, operations, etc. Also, the term "or" is used in its inclusive sense (and not its exclusive sense) when used, for example, to connect a list of elements, such that the term "or" means one, some, or all of the elements in the list. In addition, the articles "a," "an," and "the," as used in this application and the appended claims, are to be construed to mean "one or more" or "at least one," unless otherwise specified. Similarly, although operations may be depicted in the figures in a particular order, it should be recognized that such operations need not be performed in the particular order depicted, or in sequential order, or that all of the illustrated operations need not be performed, to achieve desirable results. Additionally, the figures may diagrammatically depict one or more exemplary processes in the form of a flow chart. However, other operations not depicted may also be incorporated within the diagrammatically illustrated exemplary methods and processes. For example, one or more additional operations may be performed before, after, simultaneously with, or during any of the illustrated operations.In addition, operations may be rearranged or reordered in other embodiments. In some situations, multitasking and parallel processing may be advantageous. Furthermore, the separation of various system components in the embodiments described above should not be understood as requiring such separation in all embodiments, and it should be understood that the program components and systems described may generally be integrated together in a single software product or packaged into multiple software products. Additionally, other implementations are within the scope of the following claims. In some cases, the actions recited in the claims can be performed in a different order and still achieve desirable results.

[0127] Thus, the claims are not intended to be limited to the implementations shown herein but are to be accorded the widest scope consistent with the disclosure, the principles and novel features disclosed herein.

Claims

1. A waveguide, an optically transparent layer comprising an optically transparent material and a plurality of surfaces arranged to guide light within the waveguide by total internal reflection, the light including image information; an internal coupling optical element, the internal coupling optical element configured to deflect the light into the waveguide such that the light is guided within the optically transparent layer; Equipped with The internal coupling optical element comprises: A prism and a lens integrated with the prism, the lens having a curvature to provide a refractive power to the light entering the internal coupling element and deflected thereby into the waveguide; 4. A waveguide comprising:

2. A waveguide as described in claim 1, wherein the refractive power is a positive refractive power.

3. The waveguide of claim 1, wherein the lens has a concave curvature from the viewpoint of most locations within the optically transparent layer.

4. The waveguide of claim 1, wherein each of the multiple surfaces has a surface roughness of about 0.1 nm to about 2.0 nm.

5. The waveguide of claim 1, wherein the optically transparent material comprises a polymer.

6. The waveguide of claim 1, wherein the optically transparent layer, the plurality of surfaces, and the internally coupled optical elements are monolithically integrated as a molded optic.

7. A waveguide, an optically transparent layer comprising an optically transparent material and first and second surfaces arranged to guide light within the waveguide by total internal reflection, the light including image information; a lens formed within a surface portion of the first surface, the lens being monolithically integrated with the waveguide; an internal coupling optical element configured to receive the light passing through the lens and to pivot at least a portion of the received light into the optically transparent layer to be guided therein, the internal coupling optical element being aligned with the lens such that the lens provides a refractive power to the light received by the internal coupling optical element; A waveguide comprising:

8. The waveguide of claim 7, wherein the lens is a convex lens.

9. The waveguide of claim 7, wherein the lens is a lens with positive refractive power.

10. The waveguide of claim 7, wherein the internal coupling optical element is disposed on the second surface of the optically transparent layer.

11. The waveguide of claim 7, wherein the first surface and the second surface each have a surface roughness of about 0.1 nm to about 2.0 nm.

12. The waveguide of claim 7, wherein the optically transparent material comprises a polymer.

13. The waveguide of claim 7, wherein the optically transparent layer, the first and second surfaces, and the lens are monolithically integrated as a molded optic.

14. The waveguide of claim 7, wherein the internal coupling optical element is a grating.

15. The waveguide of claim 7, wherein the internal coupling optical element is integrated with the optically transparent layer.

16. The waveguide of claim 1, wherein the internal coupling optical element does not extend completely through the optically transparent layer.

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