Apple Inc.

Jonathan B Pfeiffer

Adam C Urness

Friso Schlottau

Vikrant Bhakta

Se Baek Oh

Francesco Aieta

Mark R Ayres

Hyungryul J Choi

Christopher M Dodson

Byron R Cocilovo

Scott M Delapp

Guolin Peng

An electronic device may include a display that generates light for an optical system that redirects the light towards an eye box. The optical system may include a waveguide, a non-diffractive input coupler, a cross coupler, and an output coupler. The cross coupler may expand the light in a first direction. The cross coupler may perform an even number of diffractions on the light and may couple the light back into the waveguide at an angle suitable for total internal reflection. The output coupler may expand the light in a second direction while coupling the light out of the waveguide. The cross coupler may include surface relief gratings or holographic gratings embedded within the waveguide or formed in a separate substrate. The optical system may direct the light towards the eye box without chromatic dispersion and while supporting an expanded field of view and optical bandwidth.

Optical systems with light-expanding couplers

An electronic device may include a waveguide with an input coupler and an output coupler. The input coupler may receive the image light from imaging optics. The input coupler may be an input coupling prism and the imaging optics may include lens elements. World light may be viewable at an eye box through the output coupler. Biasing, compensation, and/or prescription lenses may overlap the output coupler. The input coupling prism, the lens elements in the imaging optics, and/or one or more of the biasing, compensation, and prescription lenses may be formed from gradient index (GRIN) material. The GRIN material may have a gradient refractive index that varies in one or more gradient directions. Use of GRIN materials may minimize the volume required to form the device without sacrificing optical performance. In addition, the GRIN materials may compensate for dispersion and aberrations in the device.

Optical systems having gradient index optical structures

An electronic device may include a display with an optical combiner. The combiner may include a waveguide and a cross coupler on the waveguide. The combiner may redirect light from a display module to an eye box while passing world light to the eye box within a field of view. The cross coupler may include surface relief gratings or other broadband gratings. The combiner may include an angular filter that at least partially overlaps the cross coupler. The cross coupler may include surface relief grating structures or other broadband gratings. The angular filter may include angled absorbers or diffractive gratings. The angular filter may prevent world light that would otherwise produce distracting flares at the eye box (e.g., world light incident on the waveguide outside the field of view such as high-incident angle light from an overhead light source) from passing to the cross coupler.

Optical systems with flare-mitigating angular filters

A display may include a waveguide. An input coupler may couple image light into the waveguide and an output coupler may couple the image light out of the waveguide. A surface relief grating on the waveguide may couple infrared light into the waveguide and may couple the infrared light out of the waveguide. The surface relief grating may additionally or alternatively couple reflected infrared light into the waveguide and out of the waveguide and towards an infrared sensor. The surface relief grating may also form a cross-coupler for the image light. The infrared sensor may gather infrared sensor data based on the reflected infrared light. Control circuitry may perform gaze tracking operations based on the infrared sensor data. The input and output couplers may also be formed from surface relief gratings or may include other optical components.

Waveguide display with gaze tracking

Systems and methods of dispersion compensation in an optical device are disclosed. A holographic optical element may include a set of different holograms in a grating medium. Each hologram in the set may have a corresponding grating vector with a grating frequency and direction. The directions of the grating vectors may vary as a function of the grating frequency. Different holograms in the set may diffract light in a particular direction so that the light emerges from a boundary of the grating medium in a single given direction regardless of wavelength. A prism may be used to couple light into the grating medium. The prism may be formed using materials having dispersion properties that are similar to the dispersion properties of the grating material. The prism may have an input face that receives perpendicular input light. The prism may include multiple portions having different refractive indices.

Optical system with dispersion compensation

A head-mounted electronic device may include a display with an optical combiner. The combiner may include a waveguide with first and second output couplers. The first output coupler may couple a first portion of image light at visible wavelengths out of the waveguide and towards an eye box. The second output coupler may couple a second portion of the image light at near-infrared wavelengths out of the waveguide and towards the surrounding environment. The second portion of the image light may include an authentication code that is used by a secondary device to authenticate the head-mounted device and/or may include a pattern that serves to prevent camera equipment in the surrounding environment from capturing accurate facial recognition information from a user while wearing the head-mounted device.

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Lafayette, CO, United States of America

Jonathan B Pfeiffer