Optical modulator and image projector based on leaky-mode waveguide with spatial multiplexing
AssigneeMeta Platforms Technologies, LLC
InventorsSundeep Kumar Jolly, Sihui He
Life of this patent
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Abstract
A leaky-mode acousto-optical modulator may be used to generate visual images suitable for direct viewing, without image-forming optics. To extend a field of view of the modulator to limits suitable for visual displays, an array of acoustic transducers is coupled to a waveguide along its length. Each acoustic transducer generates an acoustic wave causing a corresponding leaky mode to appear. A reflector is disposed proximate each transducer for directing the out-coupled light portion at a unique angle, providing a corresponding field of view portion for that direction. The field of view portions coalesce into a continuous synthetic field of view suitable for wide-angle visual display applications.
Claims20
An optical modulator comprising:
- a waveguide for guiding a light beam therein in a first direction;
- an array of transducers coupled to the waveguide along the first direction, each transducer configured to provide, responsive to a driving signal, an acoustic wave in the waveguide, the acoustic wave exciting a leaky mode of propagation of the light beam in the waveguide resulting in out-coupling of a portion of the light beam from the waveguide;
- and
- an array of reflectors for redirecting the light beam portions out-coupled by the array of transducers from the waveguide, wherein different out-coupled portions are redirected at different angles to provide a compound cone of directions based on a spectrum of an image generated by an image projector.
An image projector comprising:
- a light source for providing a light beam;
- a waveguide comprising an in-coupler for in-coupling the light beam to propagate in the waveguide in a first direction;
- an array of transducers coupled to the waveguide along the first direction, each transducer configured to provide, responsive to a driving signal, an acoustic wave in the waveguide, the acoustic wave exciting a leaky mode of propagation of the light beam in the waveguide resulting in out-coupling of a portion of the light beam from the waveguide;
- and
- an array of reflectors for redirecting the light beam portions out-coupled by the array of transducers from the waveguide and toward an exit pupil of the image projector, wherein different out-coupled portions are redirected at different angles to provide a compound cone of directions based on a spectrum of an image generated by the image projector.
A method for forming an image in angular domain, the method comprising:
- in-coupling a light beam into a waveguide to propagate in the waveguide in a first direction;
- using an array of transducers coupled to the waveguide along the first direction to provide a plurality of acoustic waves in the waveguide, each acoustic wave exciting a leaky mode of propagation of the light beam in the waveguide resulting in out-coupling of a portion of the light beam from the waveguide;
- and
- using an array of reflectors to redirect the light beam portions out-coupled by the array of transducers from the waveguide, wherein different out-coupled portions are redirected at different angles to provide a compound cone of directions based on a spectrum of an image generated by an image projector.
Dependencies are inferred from the claim text.