A waveguide display having an input image generator providing image light projected over a field of view; a waveguide having first and second external surfaces; and at least one grating optically coupled to the waveguide for extracting light towards a viewer. The waveguide has a lateral refractive index variation between said external surfaces that prevents any ray propagated within the waveguide from optically interacting with at least one of the external surfaces.

An optical device includes a light source configured to provide illumination light and a waveguide. The waveguide has an input surface, an output surface distinct from and non-parallel to the input surface, and an output coupler. The waveguide is configured to receive, at the input surface, the illumination light provided by the light source and propagate the illumination light via total internal reflection. The waveguide is also configured to redirect, by the output coupler, the illumination light so that the illumination light is output from the output surface for illuminating a spatial light modulator.

Optical combiners are provided. The optical combiner may have a see through optically transparent substrate and a patterned region included in the optically transparent substrate and disposed along a wave propagation axis of the substrate. The patterned region may be partially optically reflective and partially optically transparent. The patterned region may comprise a plurality of optically transparent regions of the optically transparent substrate and a plurality of optically reflective regions inclined relative to the optical transparent substrate wave propagation axis. Augmented reality optical apparatus, such a head up display, may include the optical combiner.

Images perceived to be substantially full color or multi-colored may be formed using component color images that are distributed in unequal numbers across a plurality of depth planes. The distribution of component color images across the depth planes may vary based on color. In some embodiments, a display system includes a stack of waveguides that each output light of a particular color, with some colors having fewer numbers of associated waveguides than other colors. The stack of waveguides may include by multiple pluralities (e.g., first and second pluralities) of waveguides, each configured to produce an image by outputting light corresponding to a particular color. The total number of waveguides in the second plurality of waveguides is less than the total number of waveguides in the first plurality of waveguides, and may be more than the total number of waveguides in a third plurality of waveguides, in embodiments where three component colors are utilized.

A light guide includes light guiding members including first and second light guiding members, an optical entrance having a plane on which the light is incident, a light guiding unit to guide the light incident on the optical entrance with repeated reflection, a light beam ejection unit to eject the light to an outside of the light guide, and an extraction unit to reflect the light guided by the light guiding unit toward the light beam ejection unit. The light guiding members guide and eject a light, and the second light guiding member is bonded to, at least, the light guiding unit of the first light guiding member.

Examples are disclosed that relate to calibration of a stereoscopic display system of an HMD via an optical calibration system comprising a waveguide combiner. One example provides an HMD device comprising a first image projector and a second image projector configured to project a stereoscopic image pair, and an optical calibration system. The optical calibration system comprises a first optical path indicative of an alignment of the first image projector, a second optical path indicative of an alignment of the second image projector, a waveguide combiner in which the first and second optical paths combine into a shared optical path, and one or more boresight sensors configured to detect calibration image light traveling along one or more of the first optical or the second optical path.

A display system includes a waveguide plate comprising an in-coupling grating, an expansion grating, and a sampling grating. The display system includes a projection system configured to direct input light toward the in-coupling grating. The in-coupling grating is configured to diffract the input light to propagate within the waveguide plate. The in-coupling grating is configured to (i) cause a display portion of the input light to propagate toward the expansion grating in a manner that avoids diffraction by the expansion grating and (ii) cause a sampling portion of the input light to propagate toward the sampling grating. The expansion grating is configured to (i) diffract the display portion of the input light to cause the display portion of the input light to continue to propagate within the waveguide plate. The sampling grating is configured to diffract the sampling portion of the input light outward from the waveguide plate.

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.

A method for displaying virtual content to a user, the method includes determining an accommodation of the user's eyes. The method also includes delivering, through a first waveguide of a stack of waveguides, light rays having a first wavefront curvature based at least in part on the determined accommodation, wherein the first wavefront curvature corresponds to a focal distance of the determined accommodation. The method further includes delivering, through a second waveguide of the stack of waveguides, light rays having a second wavefront curvature, the second wavefront curvature associated with a predetermined margin of the focal distance of the determined accommodation.

An augmented reality headset may include a reflective holographic combiner to direct light from a light engine into a user's eye while also transmitting light from the environment. The combiner and engine may be arranged to project light fields with different fields of view and resolution to match the visual acuity of the eye. The combiner may be recorded with a series of point to point holograms; one projection point interacts with multiple holograms to project light onto multiple eye box points. The engine may include a laser diode array, a distribution waveguide, scanning mirrors, and layered waveguides that perform pupil expansion and that emit wide beams of light through foveal projection points and narrower beams of light through peripheral projection points. The light engine may include focusing elements to focus the beams such that, once reflected by the holographic combiner, the light is substantially collimated.