An exit pupil expander (EPE) has entrance and exit pupils, a back surface adjacent to the entrance pupil, and an opposed front surface. In one embodiment the EPE is geometrically configured such that light defining a center wavelength that enters at the entrance pupil perpendicular to the back surface experiences angularly varying total internal reflection between the front and back surfaces such that the light exiting the optical channel perpendicular to the exit pupil is at a wavelength shifted from the center wavelength. In another embodiment a first distance at the entrance pupil between the front and back surfaces is different from a second distance at the exit pupil between the front and back surfaces. The EPE may be deployed in a head-wearable imaging device (e.g., virtual or augmented reality) where the entrance pupil in-couples light from a micro display and the exit pupil out-couples light from the EPE.

A wearable device may include a head-mounted display (HMD) for rendering a three-dimensional (3D) virtual object which appears to be located in an ambient environment of a user of the display. The relative positions of the HMD and one or more eyes of the user may not be in desired positions to receive, or register, image information outputted by the HMD. For example, the HMD-to-eye alignment vary for different users and may change over time (e.g., as a given user moves around or as the HMD slips or otherwise becomes displaced). The wearable device may determine a relative position or alignment between the HMD and the user's eyes by determining whether features of the eye are at certain vertical positions relative to the HMD. Based on the relative positions, the wearable device may determine if it is properly fitted to the user, and provides feedback on the quality of the fit to the user, and may take actions to reduce or minimize effects of any misalignment.

There is disclosed herein a waveguide comprising an optical slab and an optical wedge. The optical slab has a first refractive index, n.sub.1>1. The optical slab comprises: a pair of opposing surfaces and an input port. The pair of opposing surfaces are arranged in a parallel configuration. The input port is arranged to receive light into the optical slab at an angle such that the light is guided between the first and second opposing surfaces by a series of internal reflections. The optical wedge has a second refractive index, n.sub.2, wherein 1<n.sub.2<n.sub.1. The optical wedge comprises a pair of opposing surfaces arranged in a wedge configuration. A first surface of the optical wedge abuts the second surface of the optical slab to form an interface that allows partial transmission of light guided by the optical slab into the optical wedge at a plurality of points along the interface such that the light is divided a plurality of times. The angle of the wedge allows light received at the interface to escape through the second surface of the optical wedge such that the exit pupil of the waveguide is expanded by the plurality of divisions of the light.

Systems, devices, and methods for expanding the eyebox of a wearable heads-up display are described. A light guide with an expanded eyebox includes a light guide material, an in-coupler, an outcoupler, and a gradient refractive index (GRIN) material. The in-coupler and the out-coupler may comprise a GRIN material. An eyeglass lens with expanded eyebox includes a light guide with expanded eyebox. A wearable heads-up display includes an eyeglass lens including a light guide with an expanded eyebox.

In a general aspect, a structured optical beam with position-dependent polarizations is prepared for human observation. In some examples, an optics method includes processing an optical beam to produce a structured optical beam for human observation. Processing the optical beam includes receiving the optical beam from a laser source; attenuating the optical beam to an exposure irradiance level that is safe for direct viewing by a human eye; expanding the optical beam to a size configured for a field of view of the human eye; and preparing the optical beam with a position-dependent polarization profile. The structured optical beam, which has the position-dependent polarization profile, is directed towards an observation region for human observation.

An optical assembly of an imaging device includes an array of lens assemblies each having a double-folded optical axis, and an image sensor. Each of the lens assemblies each having the double-folded optical axis includes an input optical axis folding element, at least one lens having an optical power, and an output optical axis folding element. The input optical axis folding element of each of the lens assemblies having the double-folded optical axis is configured to change a field of view (FOV) of the input optical axis folding element by changing an optical axis folding angle of the input optical axis folding element about two axes.

An optical targeting device comprised of a support body, an imaging waveguide joined to and in a position relative to the support body, and a light source mounted on the support body. The imaging waveguide is comprised of an input diffractive optic, and an output diffractive optic. The light source is located to direct a targeting light beam to the input diffractive optic of the imaging waveguide. In operation of the optical targeting device, the imaging waveguide simultaneously transmits incoming light from a scene viewable by a user of the device through the light transmissive body, and propagates the targeting light beam from the input diffractive optic laterally through the light transmissive body and directs the targeting light beam outwardly from the output diffractive optic, thereby rendering the targeting light beam as a point of light superimposed within the scene viewable by the user.

To improve brightness of image information visually recognized by a user while using plastic for a light guide plate. An image display element includes: a substrate made of resin; an incident diffraction grating that diffracts incident light; and an exit diffraction grating that emits the light, the incident diffraction grating being formed on a first surface of the substrate, the exit diffraction grating being formed on a second surface on a side opposite to the first surface of the substrate, and the exit diffraction grating being formed on one surface.

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.

Provided are a Fourier-beam shaper and a display apparatus including the Fourier-beam shaper. The Fourier-beam shaper includes: a waveguide; an input coupler configured to direct a plurality of light beams toward the waveguide in a time-sequential manner; and a spatial converter configured to output the plurality of light beams traveling in the waveguide through spatially different regions of the spatial converter.