Large scale steerable coherent optical switched arrays
Aspects of the present disclosure describe large scale steerable optical switched arrays that may be fabricated on a common substrate including many thousands or more emitters that may be arranged in a curved pattern at the focal plane of a lens thereby allowing the directional control of emitted light and selective reception of reflected light suitable for use in imaging, ranging, and sensing applications including accident avoidance.
1. An optical structure comprising:
a plurality of optical waveguides integrated onto a photonic substrate;
a plurality of optical emitter structures connected to respective ones of the optical waveguides, each optical emitter structure configured to emit a light beam from the photonic substrate toward an emitting aperture; and
an optical power distribution network optically connecting a light source to the plurality of optical waveguides, said optical power distribution network including a plurality of switches;
wherein said switches are configured such that, over at least a first time interval, optical power emitted from the light source that enters the optical power distribution network in different time slots within the first time interval will be emitted from different subsets of the plurality of optical emitter structures toward the emitting aperture.
2. The optical structure of claim 1 wherein the plurality of switches are organized into levels of switches and switches at a same level are all switched simultaneously.
3. The optical structure of claim 1 wherein the plurality of optical emitter structures are arranged along a common arc.
4. The optical structure of claim 1 wherein the plurality of switches are organized into levels and switches at one level operate at a speed different from the speed of operation for switches at a different level.
5. The optical structure of claim 4 wherein the switches proximate to the plurality of optical emitter structures operate at the slowest speed(s).
6. The optical structure of claim 1 further comprising an optical element positioned in the emitting aperture in the optical path of the emitted optical power.
7. The optical structure of claim 6 wherein the optical element comprises a lens.
8. The optical structure of claim 7 wherein the optical element further comprises a grating and the grating is positioned in the optical path of the emitted optical power between one of the plurality of optical emitter structures and the lens.
9. The optical structure of claim 7 wherein the lens is configured and positioned to focus optical power from each one of the plurality of optical emitter structures.
10. The optical structure of claim 6 wherein the optical element is configured and positioned to receive optical power from each one of the plurality of optical emitter structures.
11. The optical structure of claim 6 wherein the optical element comprises at least one grating.
12. The optical structure of claim 1 wherein the optical power distribution network is a tree network and the switches include at least one of: one or more 1×2 switches, one or more 1×3 switches, one or more 1×4 switches, one or more 2×2 switches, or one or more 2×3 switches.
13. The optical structure of claim 1 wherein the optical power distribution network and the plurality of optical emitter structures are fabricated on the photonic substrate.
14. The optical structure of claim 1 wherein the optical power distribution network, the plurality of optical emitter structures, and the light source are all resident on the photonic substrate.
15. The optical structure of claim 1 further comprising a coherent receiver.
16. The optical structure of claim 1 wherein at least one of the switches is one selected from the group consisting of thermo-optic and electro-optic switch(es).
17. The optical structure of claim 1 wherein each one of the plurality of optical emitter structures is one selected from the group consisting of: an optical grating, plasmonic emitter, metal antennae, and mirror facet.
18. The optical structure of claim 1 further comprising a plurality of focusing gratings, where two or more of the plurality of optical emitter structures is each configured to direct optical power to a corresponding one of the plurality of focusing gratings.
19. The optical structure of claim 1 wherein the plurality of optical emitter structures are configured to emit from positions arranged over two dimensions of a plane.
20. The optical structure of claim 19 further comprising an optical element positioned in the optical path of the emitted optical power and configured to produce a substantially flat focal plane coincident with the plane over which the positions of the plurality of optical emitter structures are arranged.