Abstract: An apparatus includes a waveguide and one or more partially reflective surfaces embedded inside the waveguide, wherein each of the one or more partially reflective surfaces includes a multi-layer coating structure, wherein a first portion of the multi-layer coating structure induces an overall phase shift of light propagating through the first portion of the multi-layer coating structure and wherein a second portion of the multi-layer coating structure is selected to decrease the overall phase shift.

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: Optical sample characterization facilitates measurement and testing at any angle in a full range of angles of light propagation through an optical sample, such as a coated glass plate, having a higher than air index of refraction. A rotatable assembly includes a cylinder having a hollow, and a receptacle including the hollow. The receptacle also contains a fluid with a known refractive index. An optical light beam is input normal to the surface of the cylinder, travels through the cylinder, then via the fluid, to the optical sample, where light beam is transmitted and/or reflected, then exits the cylinder and is collected for analysis. Due at least in part to the fluid surrounding the optical sample, the optical sample can be rotated through a full range of angles (±90°, etc.) for full range testing of the optical sample.

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: In an embodiment, an apparatus is disclosed that includes at least one processor configured to determine a target coupling-out facet, identify an optical path to the target coupling-out facet, identify an active wave plate corresponding to the optical path, determine a target state of the active wave plate that corresponds to the optical path, set the active wave plate to the identified target state and cause a projection device to project a light beam comprising an image field of view component along the identified optical path.

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: An optical system includes a light-guide optical element (LOE) (10) having mutually-parallel first and second major external surfaces (11, 12) for guiding light by internal reflection, and a projector (100) that projects illumination corresponding to a collimated image from an aperture (101). The projector injects light in to the LOE via a coupling prism (30) attached to the first major external surface (11) that projects an image injection surface. A reflective polarizing beam splitter (51) is deployed at an interface between the major external surface (11) and the coupling prism (30) parallel to the major external surfaces, to selectively transmit illumination from the coupling prism into the LOE while trapping light already within the LOE so as to propagate within the LOE by internal reflection.

Abstract: Optical sample characterization facilitates measurement and testing at any angle in a full range of angles of light propagation through an optical sample, such as a coated glass plate, having a higher than air index of refraction. A rotatable assembly includes a cylinder having a hollow, and a receptacle including the hollow. The receptacle also contains a fluid with a known refractive index. An optical light beam is input normal to the surface of the cylinder, travels through the cylinder, then via the fluid, to the optical sample, where light beam is transmitted and/or reflected, then exits the cylinder and is collected for analysis. Due at least in part to the fluid surrounding the optical sample, the optical sample can be rotated through a full range of angles (±90°, etc.) for full range testing of the optical sample.

Abstract: Disclosed herein is a method for validating parallelism of internal facets of a sample. The method includes: (i) providing a sample including a light transmissive substrate and internal facets, nominally parallel and nominally inclined at an angle ?nom relative to a flat surface of the sample; (ii) providing a prism having a substantially same refractive index as the substrate and including a flat, first surface and a flat, second surface, opposite to the first surface and inclined relative thereto at substantially the angle ?nom; (iii) positioning the sample and the prism, such that the surface of the sample is parallel and adjacent to the second surface of the prism; (iv) projecting on the first surface of the prism, substantially normally thereto an incident light beam; (v) sensing light returned from the prism following reflection off the internal facets; and (vi) computing deviation from parallelism between the internal facets.

Abstract: In an embodiment, an apparatus is disclosed that includes at least one processor configured to determine a target coupling-out facet, identify an optical path to the target coupling-out facet, identify an active wave plate corresponding to the optical path, determine a target state of the active wave plate that corresponds to the optical path, set the active wave plate to the identified target state and cause a projection device to project a light beam comprising an image field of view component along the identified optical path.

Abstract: A method of fabricating a light-guide optical element having a plurality of partially reflecting surfaces is disclosed. The method includes providing a plurality of transparent plates, each plate polished on two opposite surfaces such that the surfaces are parallel to each other, coating a first of the surfaces of a subset of plates with a first coating, coating a second of the surfaces of the subset of plates with a second coating; bonding together the plurality of transparent plates to form a stack, and cutting the stack along parallel planes obliquely angled to the faces of the transparent plates so as to form the optical element, wherein the first coating is a partially reflective coating have a first set of mechanical properties, and the second coating is selected from the group consisting of: a coating similar to the first coating and a non-reflective coating having a second set of mechanical properties substantially similar to the first set of mechanical properties.

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: 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: A collimated image projector that receives light from an illuminating source and propagates the light along a light path towards an exit pupil, the projector comprising: a first homogeneous dielectric polarizing beam splitter (PBS) deployed along the light path and defining a first transition from a first light path segment to a second light path segment; a second homogeneous dielectric PBS deployed parallel to the first PBS along the second light path segment and defining a second transition from the second light path segment to a third light path segment; and collimating optics deployed along the light path after the second PBS so as to direct a collimated image towards the exit pupil; wherein the first and second PBSs are deployed such that either the first and second transitions are both performed via transmission, or the first and second transitions are both performed via reflection.

Abstract: A method of fabricating a light-guide optical element having a plurality of partially reflecting surfaces is disclosed. The method includes providing a plurality of transparent plates, each plate polished on two opposite surfaces such that the surfaces are parallel to each other, coating a first of the surfaces of a subset of plates with a first coating, coating a second of the surfaces of the subset of plates with a second coating; bonding together the plurality of transparent plates to form a stack, and cutting the stack along parallel planes obliquely angled to the faces of the transparent plates so as to form the optical element, wherein the first coating is a partially reflective coating have a first set of mechanical properties, and the second coating is selected from the group consisting of: a coating similar to the first coating and a non-reflective coating having a second set of mechanical properties substantially similar to the first set of mechanical properties.

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 may include (1) a light-guide optical element formed from transparent material and having at least first and second mutually-parallel major external surfaces for supporting propagation of an image by internal reflection, and (2) a mediating layer adjacent at least one of the at least first and second mutually-parallel major external surfaces, the mediating layer configured such that (1) reflectivity, averaged over the visible spectrum, of light coupled into the LOE and transmitted between the at least first and second mutually-parallel major external surfaces at angles below the critical angle is higher than the reflectivity that would have been expected absent the mediating layer and (2) reflectivity of purely white light lies closer to a purely white color point for an angular range from angles below the critical angle to the critical angle than the reflectivity that would have been expected absent the mediating layer.

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: An optical system may include (1) a light-guide optical element formed from transparent material and having at least first and second mutually-parallel major external surfaces for supporting propagation of an image by internal reflection, and (2) a mediating layer adjacent at least one of the at least first and second mutually-parallel major external surfaces, the mediating layer configured such that (1) reflectivity, averaged over the visible spectrum, of light coupled into the LOE and transmitted between the at least first and second mutually-parallel major external surfaces at angles below the critical angle is higher than the reflectivity that would have been expected absent the mediating layer and (2) reflectivity of purely white light lies closer to a purely white color point for an angular range from angles below the critical angle to the critical angle than the reflectivity that would have been expected absent the mediating layer.

Abstract: Disclosed herein is a method for validating parallelism of internal facets of a sample. The method includes: (i) providing a sample including a light transmissive substrate and internal facets, nominally parallel and nominally inclined at an angle ?nom relative to a flat surface of the sample; (ii) providing a prism having a substantially same refractive index as the substrate and including a flat, first surface and a flat, second surface, opposite to the first surface and inclined relative thereto at substantially the angle ?nom; (iii) positioning the sample and the prism, such that the surface of the sample is parallel and adjacent to the second surface of the prism; (iv) projecting on the first surface of the prism, substantially normally thereto an incident light beam; (v) sensing light returned from the prism following reflection off the internal facets; and (vi) computing deviation from parallelism between the internal facets.