Abstract: Disclosed herein is a method including: (i) providing a light transmissive sample including nominally parallel internal facets, which are about perpendicular to an external surface of the sample; (ii) providing an optical element having a refractive index about equal to that of the sample and including an external first surface and an external second surface acutely inclined relative thereto; (iii) positioning the second surface of the optical element adjacent to the first surface of the sample; (iv) impinging light beams on the first surface of the optical element, about normally thereto; (v) sensing light beams, which exit out of the sample following passage of the impinging light beams via the optical element, transmission thereof into the sample, reflection once off the internal facets, and exit out of the sample; and (vi) based on the sensed data, computing a deviation from parallelism between the internal facets.

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: In an embodiment, an apparatus is disclosed that includes at least one processor configured to determine a target portion of an eye motion box and to identify a facet of a light-guide optical element that is configured to direct a light beam comprising at least a portion of an image field of view toward the target portion of the eye motion box. The at least one processor is configured to identify a display region of an image generator that is configured to inject the light beam into the light-guide optical element at an angle that, in conjunction with the identified facet, is configured to direct the light beam toward the target portion of the eye motion box. The at least one processor is configured to selectively activate the identified facet and the identified display region to direct the light beam toward the target portion of the eye motion box.

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 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 light-transmitting substrate has at least two major surfaces and is deployed with a first of the major surfaces in facing relation to an eye of a viewer. A light redirecting arrangement is associated with the light-transmitting substrate and deflects light from the eye toward an optical sensor that senses light, such that the light deflection occurs at the light-transmitting substrate and the deflected light that reaches the optical sensor is unguided by the light-transmitting substrate. A processor derives current gaze direction of the eye by processing signals from the optical sensor.

Abstract: A method of moderating chromaticity of ambient light in an environment reflected back into the environment by a component comprised in a lens of glasses through which a user of views the environment, the method comprising: determining a first set of tristimulus values that characterizes ambient light reflected by the component surface as a function of angle of reflection ? in a bounded span of angles of reflection; determining a second set of tristimulus values for angles in the bounded span of angles so that light characterized by the second set of tristimulus values combined with light reflected by the component would be perceived substantially as white light; and providing an optical coating that reflects ambient light from the environment so that the reflected light is substantially characterized by the second set of tristimulus values.

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 device includes a lightguide having a first pair of external surfaces parallel to each other, and at least two sets of facets. Each of the sets including a plurality of partially reflecting facets parallel to each other, and between the first pair of external surfaces. In each of the sets of facets, the respective facets are at an oblique angle relative to the first pair of external surfaces, and at a non-parallel angle relative to another of the sets of facets. The optical device is particularly suited for optical aperture expansion.

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 head-mounted augmented reality device (10) includes a pair of optical modules (12) for the right and left eyes of the user, each having a collimating display source (14) optically coupled to a light guide (16) for directing image illumination towards an eye of the user. A support structure (20) is supported by the head of the user. An optical bench (22) provides a first set of alignment features (26, 28, 32, 74) for aligning and affixing the right optical module and a second set of alignment features (26, 28, 32, 74) for aligning and affixing the left optical module. A suspension arrangement suspends the optical bench relative to the support structure. The optical bench (22) provides the sole mechanical connection between the pair of optical modules (12) and the support structure (20).

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 first dichroic beamsplitter is deployed in a first prism on a plane oblique to a light-wave entrance surface. A second dichroic beamsplitter is deployed in a second prism on a plane oblique to a light-wave entrance surface such that polarized light in a first polarization state relative to the first dichroic beamsplitter is in a second polarization state relative to the second dichroic beamsplitter. The first dichroic beamsplitter transmits polarized light of a first color in the first polarization state relative to the first dichroic beamsplitter, and reflects polarized light of a second color in the first polarization state relative to the first dichroic beamsplitter. The second dichroic beamsplitter transmits polarized light of the first and second colors in a second polarization state relative to the second dichroic beamsplitter, and reflects polarized light of a third color in the first polarization state relative to the second dichroic beamsplitter.

Abstract: A light pipe includes at least two optical structures having different refractive indices. An interface between the two optical structures is oblique to a longitudinal axis of the light pipe such that an output ray from an output surface at a distal end of the light pipe is non-parallel to an input ray that is parallel to the longitudinal axis at an input surface at a proximal end of the light pipe. Light refracts inside the light pipe between the (at least) two optical structures altering the direction of an optical path of the light through the light pipe, thereby allowing higher degrees of freedom for the selection of the angle of deviation (folding angle) of the light pipe. By optimizing various parameters of the light pipe, a desired output optical axis angle (i.e., folding angle) can be achieved that suits the desired optical engine envelope.

Abstract: A display includes a light-guide optical element (LOE) (20) and a projector arrangement (10a) for injecting an image into the LOE so as to propagate within the LOE by internal reflection at a pair of major faces. The image is coupled out from the LOE by a coupling-out arrangement, exemplified here as internal partially-reflecting surfaces (22b). The image is coupled out from the LOE in a direction away from the eye of the observer (24b), and a reflector (30) reflects the coupled-out image back through the LOE (32), towards the eye of the observer (26). Reflector (30) is preferably a selective partial reflector, and may be convex to provide a desired apparent image distance.

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: A method for producing light-guide optical elements (LOEs) (16, 18, 56, 58) each having a set of mutually-parallel partially-reflecting surfaces (17) located between, and oriented non-parallel to, a pair of major external surfaces, and at least one region (30a, 30b, 30c) without partially-reflecting surfaces. The method includes bonding together parallel-faced plates (4) at interfaces to form a stack (42) of plates with partially-reflecting coatings between them. The stack is cut and polished to form a boundary plane (48, 48a, 48b) intersecting the interfaces, and a block (50, 50a, 50b) of transparent material is bonded to the stack. The resulting precursor structure (52, 52?) is sliced along parallel planes to form slices, each containing a part of the stack for the active region of the LOE and a part of the block.

Abstract: A display system (500) for displaying an image to an eye of a user includes a light-guide optical element (LOE) (506) and an image projector (512) projecting image illumination of a collimated image into the LOE. The image projector includes an electrically-controllable variable lens (10, 13, 71, 77, 58A, 58B, 59, 58C, 58D, 58E, 58F1, 58F2, 58G1, 58G2, 58H, 1223). A controller (18) determines a current region of interest of the image, either from tracking of the user's eye or by analysis of the image content, and controls the variable lens so as to reduce aberrations in the current region of interest at the expense of increased aberration in at least one area of the image outside the current region of interest.

Abstract: A light-guide device includes a light guiding element (13) with a number of faces, including two parallel faces (26), for guiding light by internal reflection. A transparent optical element (19) has an interface surface for attachment to a coupling surface (14) of the light guiding element, and is configured such that light propagating within the transparent optical element passes through the interface surface and the coupling surface (14) so as to propagate within the light guiding element (13). A non-transparent coating (15) is applied to at least part of one or more faces of the light guiding element (13), defining an edge (17) adjacent to, or overlapping, the coupling surface (14) of the light guiding element (13). A quantity of transparent adhesive is deployed between the coupling surface and the interface surface so as to form an optically transmissive interface. An overspill region 31 of the adhesive extends to, and overlaps, the edge (17).

Abstract: A light-transmitting substrate has parallel surfaces deployed with a first of the parallel surfaces in facing relation to an eye. An optical element is associated with the first surface and applies optical power to incident light of a first type so as to collimate the incident light, and applies substantially no optical power to incident light of a second type. An optical coupling configuration is associated with the substrate and is configured for coupling-in a proportion of collimated light of the first type incident on the first surface so as to propagate within the substrate, and for coupling-out a proportion of light of the second type propagating within the substrate. Optics associated with the substrate convert collimated light of the first type into converging beams of light, which are sensed by an optical sensor. A processor derives current gaze direction of the eye by processing signals from the optical sensor.