Slab waveguide and projector with intermodal coupling
AssigneeMeta Platforms Technologies, LLC
InventorsAlexander Koshelev, Giuseppe Calafiore
Life of this patent
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Abstract
A compact collimator or projector includes a waveguide having a slab core structure supporting at least two lateral modes of propagation. A light beam coupled into a first mode propagates to an edge of the waveguide where it is reflected by a reflector to propagate back. Upon propagation back and forth, the light is converted into a second mode. An out-coupling region, such as an evanescent coupler, is provided to out-couple the light propagating in the second mode. The reflector may have focusing power to collimate the out-coupled light beam. The light beam may be converted from the first to the second mode without being reflected from a reflector.
Claims20
A near-eye display waveguide comprising:
- a slab core structure supporting first and second optical modes of propagation;
- an input port for receiving a light beam for propagation in the first optical mode;
- a first reflector coupled to the slab core structure for reflecting the light beam to propagate back in the slab core structure;
- and
- an out-coupling region for out-coupling the light beam reflected by the first reflector;
- wherein the waveguide is configured for conversion of the light beam from the first optical mode to the second optical mode upon propagation in the slab core structure and upon reflection from the first reflector, whereby at least a portion of the light beam is out-coupled from the waveguide at the out-coupling region.
A near-eye display waveguide comprising:
- a slab core structure supporting first and second optical modes of propagation, the slab core structure comprising an intermodal coupler for conversion of a light beam from the first optical mode to the second optical mode upon propagation in the intermodal coupler;
- an input port upstream of the intermodal coupler for receiving the light beam for propagation in the slab core structure in the first optical mode;
- and
- an out-coupling region downstream of the intermodal coupler for out-coupling light propagating in the second optical mode.
A near-eye display projector comprising:
- an array of light sources for providing light beams;
- and
- a waveguide comprising:
- a slab core structure supporting first and second optical modes of propagation;
- an input port for receiving the light beams from the array of light sources for propagation in the first optical mode;
- a reflector coupled to the slab core structure for reflecting the light beams to propagate back in the slab core structure;
- and
- an out-coupling region for out-coupling the light beams reflected by the reflector from the waveguide;
- wherein the waveguide is configured for conversion of the light beams from the first optical mode to the second optical mode upon propagation in the slab core structure and reflection from the reflector, whereby at least a portion of the light beams is out-coupled from the waveguide at the out-coupling region.
Dependencies are inferred from the claim text.