Abstract: An optical assembly for optical aperture expansion combines facet reflective technology with diffractive technology. At least two diffractive components having opposite optical power (matching) are used, so that chromatic dispersion introduced by the first diffractive component will then be cancelled by the second diffractive component. The two diffractive components are used in combination with a reflective optical component to achieve more efficient aperture expansion (for near eye display), reducing distortions and noise, while also reducing design constraints on the system and individual components, as compared to conventional techniques. The assembly eliminates and/or reduces the need for polarization management, while enabling wider field of view. In addition, embodiments can have reduced nonuniformity, as compared to conventional single technology implementations, since the distortion patterns of the two technologies do not correlate.

Abstract: A transparent substrate has two parallel faces and guides collimated image light by internal reflection. A first set of internal surfaces is deployed within the substrate oblique to the parallel faces. A second set of internal surfaces is deployed within the substrate parallel to, interleaved and in overlapping relation with the first set of internal surfaces. Each of the internal surfaces of the first set includes a first coating having a first reflection characteristic to be at least partially reflective to at least a first subset of components of incident light. Each of the internal surfaces of the second set includes a second coating having a second reflection characteristic complementary to the first reflection characteristic to be at least partially reflective to at least a second subset of components of incident light. The sets of internal surfaces cooperate to reflect all components of light from the first and second subsets.

Abstract: An optical system including a light-guide optical element (LOE) with first and second sets (204, 206) of mutually-parallel, partially-reflecting surfaces at different orientations. Both sets of partially-reflecting surfaces are located between parallel major external surfaces. A third set of at least partially-reflecting surfaces (202), deployed at the coupling-in region, receive image illumination injected from a projector (2) with an optical aperture having a first in-plane width and direct the image illumination via reflection of at least part of the image illumination at the third set of at least partially-reflective facets towards the first set of partially-reflective facets with an effective optical aperture having a second width larger than the first width.

Abstract: An optical device includes a first waveguide, having parallel first and second faces and parallel third and fourth faces forming a rectangular cross-section, that guides light by four-fold internal reflection and is associated with a coupling-out configuration that couples light out of the first waveguide into a second waveguide. The first or second face is subdivided into first and second regions having different optical characteristics. The optical device also includes a coupling-in configuration having a surface that transmits light into the first waveguide. The surface is deployed in association with a portion of the third or fourth face adjoining the second region such that an edge associated with the surface trims an input collimated image in a first dimension, and a boundary between the first and second regions trims the input collimated image in a second dimension to produce a trimmed collimated image that advances by four-fold internal reflection.

Abstract: A display for providing an image to an eye of a user has a compound light-guide arrangement formed from juxtaposed first and second slab waveguides (10, 20). Image illumination from a projector (100) is introduced, part into each waveguide, so as to propagate by internal reflection within the waveguide. A coupling-out configuration of the first waveguide (10) includes a first set of obliquely-angled internal partially-reflecting surfaces (11) in a first region of the compound light-guide arrangement for coupling-out a first part of the field of view, and a coupling-out configuration of the second waveguide (20) includes a second set of obliquely-angled internal partially-reflecting surfaces (21) in a second region of the compound light-guide arrangement, at least partially non-overlapping with the first region, for coupling-out a second part of the field of view.

Abstract: An image projector includes a spatial light modulator (SLM) (320) illuminated by light from an illumination source (316) so as to reflect light corresponding to an image. A first optical arrangement (322) with positive optical power focuses light reflected from the SLM at an image plane (324). A second optical arrangement (328) with positive optical power collimates light from the image plane (324) as a collimated output image.

Abstract: An optical aperture multiplier includes a first optical waveguide (10) having a rectangular cross-section and including partially reflecting surfaces (40) at an oblique angle to a direction of elongation of the waveguide. A second optical waveguide (20), also including partially reflecting surfaces (45) at an oblique angle, is optically coupled with the first optical waveguide (10). An image coupled into the first optical waveguide with an initial direction of propagation at an oblique coupling angle advances by four-fold internal reflection along the first optical waveguide, with a proportion of intensity of the image reflected at the partially reflecting surfaces so as to be coupled into the second optical waveguide, and then propagates through two-fold reflection within the second optical waveguide, with a proportion of intensity of the image reflected at the partially reflecting surfaces so as to be directed outwards from one of the parallel faces as a visible image.

Abstract: An optical assembly for optical aperture expansion combines facet reflective technology with diffractive technology. At least two diffractive components having opposite optical power (matching) are used, so that chromatic dispersion introduced by the first diffractive component will then be cancelled by the second diffractive component. The two diffractive components are used in combination with a reflective optical component to achieve more efficient aperture expansion (for near eye display), reducing distortions and noise, while also reducing design constraints on the system and individual components, as compared to conventional techniques. The assembly eliminates and/or reduces the need for polarization management, while enabling wider field of view. In addition, embodiments can have reduced nonuniformity, as compared to conventional single technology implementations, since the distortion patterns of the two technologies do not correlate.

Abstract: An apparatus (100) for deriving a gaze direction of a human eye (150) includes a light-guide optical element (LOE) (120) having pair of parallel faces (104a), (104b) deployed in facing relation to the eye (150). A coupling-in configuration, such as a set of partially-reflective surfaces (145), is associated with LOE (120) and configured for coupling-in a proportion of light incident on face (104a) so as to propagate within the LOE. Focusing optics (106) associated with LOE (120) converts sets of parallel light rays propagating within the LOE into converging beams of captured light which are sensed by an optical sensor (125). A processing system (108) processes signals from the optical sensor (125) to derive a current gaze direction of the eye. Despite the aperture-combining effect of the LOE, retinal images can be effectively recovered as the only image information brought to focus on the optical sensor.

Abstract: A method of polishing a target surface of a waveguide to achieve perpendicularity relative to a reference surface is disclosed. The method includes i) providing a polishing apparatus having a polishing plate with a flat surface defining a reference plane, and an adjustable mounting apparatus configured to hold the waveguide during polishing at a plurality of angular orientations; ii) positioning an optical alignment sensor and a light reflecting apparatus such that a first collimated light beam is reflected off of a surface parallel to the reference plane, and a second perpendicular collimated light beam is reflected off of the reference surface; iii) aligning the waveguide within the polishing apparatus such that the reflections received by the optical alignment sensor align within the optical alignment sensor, thereby being indicative of perpendicularity between the reference plane and the reference surface; and iv) polishing the target surface of the aligned waveguide.

Abstract: A display and method for providing an image to an eye of a viewer is provided. The display comprises at least two projector assemblies. Each projector assembly comprises a light-guide optical element (LOE), and an image projector arrangement for generating a partial image and being deployed to introduce the partial image into the LOE for coupling out towards the eye of the viewer. The at least two projector assemblies cooperate to display the image to the eye of the viewer with partial overlap. The display further comprises a controller associated with the image projector arrangements and configured to reduce a pixel intensity of selected pixels in a region of partial overlap between the first and second part of the image so as to enhance a perceived uniformity of the image.

Abstract: A transparent substrate has two parallel faces and guides collimated image light by internal reflection. A first set of internal surfaces is deployed within the substrate oblique to the parallel faces. A second set of internal surfaces is deployed within the substrate parallel to, interleaved and in overlapping relation with the first set of internal surfaces. Each of the internal surfaces of the first set includes a first coating having a first reflection characteristic to be at least partially reflective to at least a first subset of components of incident light. Each of the internal surfaces of the second set includes a second coating having a second reflection characteristic complementary to the first reflection characteristic to be at least partially reflective to at least a second subset of components of incident light. The sets of internal surfaces cooperate to reflect all components of light from the first and second subsets.

Abstract: An optical system including a light-guide optical element (LOE) with first and second sets (204, 206) of mutually-parallel, partially-reflecting surfaces at different orientations. Both sets of partially-reflecting surfaces are located between parallel major external surfaces. A third set of at least partially-reflecting surfaces (202), deployed at the coupling-in region, receive image illumination injected from a projector (2) with an optical aperture having a first in-plane width and direct the image illumination via reflection of at least part of the image illumination at the third set of at least partially-reflective facets towards the first set of partially-reflective facets with an effective optical aperture having a second width larger than the first width.

Abstract: An optical device includes a first waveguide, having parallel first and second faces and parallel third and fourth faces forming a rectangular cross-section, that guides light by four-fold internal reflection and is associated with a coupling-out configuration that couples light out of the first waveguide into a second waveguide. The first or second face is subdivided into first and second regions having different optical characteristics. The optical device also includes a coupling-in configuration having a surface that transmits light into the first waveguide. The surface is deployed in association with a portion of the third or fourth face adjoining the second region such that an edge associated with the surface trims an input collimated image in a first dimension, and a boundary between the first and second regions trims the input collimated image in a second dimension to produce a trimmed collimated image that advances by four-fold internal reflection.

Abstract: An optical system includes a partial-internal-reflection rectangular light guide (PRLG) (10) having three surfaces supporting internal reflection and a partially-reflecting fourth surface (34) with which a second light guide portion (30) is associated. A light beam redirecting arrangement, typically including a set of embedded partially-reflecting surfaces (12), in light guide portion (30) redirects light emerging from the PRLG towards a third light guide portion (20) that includes a coupling-out configuration (122), such as a further set of partially-reflecting surfaces (28), coupling-out light beams of an image towards the eye of a user.

Abstract: A display for providing an image to an eye of a user has a compound light-guide arrangement formed from juxtaposed first and second slab waveguides (10, 20). Image illumination from a projector (100) is introduced, part into each waveguide, so as to propagate by internal reflection within the waveguide. A coupling-out configuration of the first waveguide (10) includes a first set of obliquely-angled internal partially-reflecting surfaces (11) in a first region of the compound light-guide arrangement for coupling-out a first part of the field of view, and a coupling-out configuration of the second waveguide (20) includes a second set of obliquely-angled internal partially-reflecting surfaces (21) in a second region of the compound light-guide arrangement, at least partially non-overlapping with the first region, for coupling-out a second part of the field of view.

Abstract: An optical aperture multiplier includes a first optical waveguide (10) having a rectangular cross-section and including partially reflecting surfaces (40) at an oblique angle to a direction of elongation of the waveguide. A second optical waveguide (20), also including partially reflecting surfaces (45) at an oblique angle, is optically coupled with the first optical waveguide (10). An image coupled into the first optical waveguide with an initial direction of propagation at an oblique coupling angle advances by four-fold internal reflection along the first optical waveguide, with a proportion of intensity of the image reflected at the partially reflecting surfaces so as to be coupled into the second optical waveguide, and then propagates through two-fold reflection within the second optical waveguide, with a proportion of intensity of the image reflected at the partially reflecting surfaces so as to be directed outwards from one of the parallel faces as a visible image.

Abstract: A method of fabricating an optical aperture multiplier is provided. A slice and a first optical structure are obtained. The slice has external faces including a pair of parallel faces, and a first plurality of partially reflective internal surfaces oblique to the pair of parallel faces. The first optical structure has external surfaces including a planar coupling surface, and a second plurality of partially reflective internal surfaces oblique to the coupling surface. The slice is optically coupled with the first optical structure such that one of the faces of the pair of parallel faces is in facing relation with the coupling surface to form a second optical structure. At least one optical aperture multiplier is sliced from the second optical structure by cutting the second optical structure through at least two cutting planes perpendicular to the coupling surface. The optical aperture multiplier is preferably part of a near eye display augmented reality system.

Abstract: A method for generating an image in a near-eye display may include operating a light source to emit the image as incident light. The light source may be configured such that incident light as received by the light reflecting elements compensates for the chromatic reflectance of the light reflecting elements. The method may include coupling the incident light into a light-transmitting substrate, thereby trapping the light between first and second major surfaces of the light-transmitting substrate by total internal reflection and coupling the light out of the substrate by the light reflecting elements having chromatic reflectance.

Abstract: A method of polishing a target surface of a waveguide to achieve perpendicularity relative to a reference surface is disclosed. The method includes i) providing a polishing apparatus having a polishing plate with a flat surface defining a reference plane, and an adjustable mounting apparatus configured to hold the waveguide during polishing at a plurality of angular orientations; ii) positioning an optical alignment sensor and a light reflecting apparatus such that a first collimated light beam is reflected off of a surface parallel to the reference plane, and a second perpendicular collimated light beam is reflected off of the reference surface; iii) aligning the waveguide within the polishing apparatus such that the reflections received by the optical alignment sensor align within the optical alignment sensor, thereby being indicative of perpendicularity between the reference plane and the reference surface; and iv) polishing the target surface of the aligned waveguide.