Waveguide concentrator for light source
A light source or projector for a near-eye display includes a light source subassembly optically coupled to a waveguide concentrator. The light source subassembly may include several semiconductor chips each hosting an array of emitters such s superluminescent light-emitting diodes. The semiconductor chips may be disposed side-by-side, with their emitting sides or facets coupled to the waveguide concentrator, which provides a tight array of output light ports on a common output plane of the concentrator. The output diverging beams at the array of output light ports are coupled to a collimator, which collimates the beams and couples them to an angular scanner for scanning the collimated light beams together across the field of view of the display.
1. A projector comprising:
a light source subassembly comprising a substrate supporting a plurality of semiconductor light sources for providing a plurality of optical beams;
a waveguide concentrator comprising first and second end facets and a plurality of waveguides extending between the first and second end facets, wherein the waveguide concentrator is optically coupled to the light source subassembly at the first end facet for receiving and guiding the plurality of optical beams in the plurality of waveguides, and wherein spacings between the waveguides at the first end facet are larger than at the second end facet;
a collimator optically coupled to the waveguide concentrator at the second end facet thereof; and
a tiltable reflector optically coupled to the collimator for receiving and redirecting the plurality of optical beams collimated by the collimator;
wherein the collimator is configured for collimating the plurality of optical beams emitted at the second end facet of the waveguide concentrator, and for redirecting the plurality of optical beams to impinge onto the tiltable reflector.
2. The projector of claim 1 , further comprising a controller operably coupled to the light source subassembly and the tiltable reflector and configured to energize the plurality of semiconductor light sources in coordination with operating the tiltable reflector.
3. The projector of claim 1 , wherein each semiconductor light source of the plurality of semiconductor light sources comprises at least one of: a superluminescent light-emitting diode, a laser diode, a vertical-cavity surface-emitting laser diode, or a light-emitting diode.
4. The projector of claim 1 , wherein the collimator comprises a lens.
5. The projector of claim 1 , wherein the tiltable reflector comprises a microelectromechanical system (MEMS).
6. The projector of claim 1 , wherein the plurality of semiconductor light sources comprises an array of superluminescent light-emitting diodes (SLEDs).
7. The projector of claim 1 , wherein each waveguide of the plurality of waveguides forms an acute angle with the first end facet in a plane of the waveguide concentrator.
8. The projector of claim 1 , wherein the waveguides of the waveguide concentrator form a two-dimensional array of output ports at the second end facet for outputting light propagated therein.
9. The projector of claim 8 , wherein at least some of the waveguides of the waveguide concentrator extend in three dimensions.
10. The projector of claim 1 , wherein the waveguide concentrator comprises a stack of layers, wherein at least some of the waveguides of the waveguide concentrator comprise a plurality of waveguide sections disposed in different layers of the stack of layers and optically coupled by inter-layer couplers.
11. The projector of claim 1 , wherein the first and second end facets of the waveguide concentrator are disposed opposite each other.
12. The projector of claim 1 , wherein each waveguide of the plurality of waveguides has a first propagation mode at the first end facet larger than a second propagation mode at the second end facet.
13. A near-eye display comprising:
a light source subassembly comprising a substrate supporting a plurality of semiconductor light sources for providing a plurality of optical beams;
a waveguide concentrator comprising first and second ends and a plurality of waveguides extending between the first and second ends, wherein the waveguide concentrator is optically coupled to the light source subassembly at the first end for receiving and guiding the plurality of optical beams in the plurality of waveguides, and wherein spacings between the waveguides at the first end are larger than at the second end;
a collimator optically coupled to the waveguide concentrator at the second end thereof for collimating the plurality of optical beams emitted at the second end;
a tiltable reflector optically coupled to the collimator for receiving and redirecting the plurality of optical beams collimated by the collimator; and
a pupil replicator optically coupled to the tiltable reflector and configured for providing multiple laterally offset copies of the optical beams redirected by the tiltable reflector.
14. The near-eye display of claim 13 , wherein the plurality of semiconductor light sources comprises an array of superluminescent light-emitting diodes.
15. The near-eye display of claim 13 , further comprising a controller operably coupled to the light source subassembly and the tiltable reflector and configured to energize the plurality of semiconductor light sources in coordination with operating the tiltable reflector to provide an image in angular domain.
16. The near-eye display of claim 13 , wherein the tiltable reflector comprises a microelectromechanical system (MEMS) biaxially tiltable reflector.
17. The near-eye display of claim 13 , wherein each waveguide of the plurality of waveguides forms an acute angle with the first end in a plane of the waveguide concentrator.
18. The near-eye display of claim 13 , wherein the waveguides of the waveguide concentrator form a two-dimensional array of output ports at the second end for outputting light propagated therein.
19. The near-eye display of claim 18 , wherein at least some of the waveguides of the waveguide concentrator extend in three dimensions.
20. The near-eye display of claim 13 , wherein the waveguide concentrator comprises a stack of layers, wherein at least some of the waveguides of the waveguide concentrator comprise a plurality of waveguide sections disposed in different layers of the stack of layers and optically coupled by inter-layer couplers.