Tunable optical devices with integrated active switch-matrix driver circuits
According to various embodiments, a tunable optical device comprises a tunable optical metasurface on a substrate with an integrated driver circuit. In some embodiments, the tunable optical device includes a photon shield layer to prevent optical radiation from disrupting operation of the driver circuit. In some embodiments, the tunable optical device includes a diagnostic circuit to detect and disable defective optical structures of the metasurface. In some embodiments, the tunable optical device includes an integrated heater circuit that maintains a liquid crystal of the metasurface above a minimum operating temperature. In some embodiments, the tunable optical device includes an integrated lidar sequencing controller, a steering pattern subcircuit, and a photodetector circuit.
1. A tunable optical device, comprising:
a substrate;
a tunable optical metasurface comprising:
a plurality of optical structures on the substrate, and
a dielectric material with a tunable refractive index around the plurality of optical structures of the metasurface; and
an active switch-matrix driver circuit integrated within the substrate to selectively apply a voltage pattern to the plurality of optical structures to control deflection of incident optical radiation according to a target deflection pattern, wherein the active switch-matrix driver circuit includes a plurality of driver channels that are each switched between a different subset of the optical structures to allow for individual control of each optical structure.
2. The tunable optical device of claim 1 , wherein the active switch-matrix driver circuit comprises D driver channels to drive N optical structures, with each driver channel switchable between K metal optical structures, such that N=K*D, where each of D, K, and N are integer values.
3. The tunable optical device of claim 1 , wherein the optical structures comprise metal optical structures.
4. The tunable optical device of claim 1 , wherein the optical structures comprise dielectric optical structures.
5. The tunable optical device of claim 1 , wherein the plurality of optical structures of the metasurface comprises a one-dimensional array of elongated rails arranged parallel to one another with respect to an underlying optical reflector.
6. The tunable optical device of claim 1 , wherein the plurality of optical structures of the metasurface comprises a two-dimensional array of pillars that extends from an underlying optical reflector.
7. The tunable optical device of claim 6 , wherein the pillars comprise one of:
rectangular pillars, circular pillars, square pillars, and oval pillars.
8. The tunable optical device of claim 1 , further comprising:
a photon shield layer between the tunable optical metasurface and the active switch-matrix driver circuit, wherein the photon shield layer is configured to prevent optical radiation from disrupting operation of the active switch-matrix driver circuit.
9. The tunable optical device of claim 8 , wherein the photon shield layer comprises one or more of: a metal layer, an amorphous carbon layer, an organically-modified glass layer, a polymer layer, and a graphite layer.
10. The tunable optical device of claim 1 , wherein the active switch-matrix driver circuit comprises a steering pattern subcircuit to store voltage patterns corresponding to defined deflection patterns.
11. The tunable optical device of claim 1 , wherein the active switch-matrix driver circuit comprises a lidar sequencing controller integrated within the substrate to sequentially drive the tunable optical metasurface according to a sequence of defined deflection patterns for targeted lidar operation.
12. The tunable optical device of claim 1 , wherein the dielectric material with the tunable refractive index comprises one or more of: liquid crystal, an electro-optic polymer, a chalcogenide glass, and a semiconductor material.
13. The tunable optical device of claim 1 , further comprising:
a diagnostic circuit integrated within the substrate to:
test an electrical characteristic of at least some of the optical structures,
identify an optical structure that is defective, and
disable at least the identified defective optical structure.
14. A tunable optical device, comprising:
a substrate;
a tunable optical metasurface comprising:
a plurality of optical structures on the substrate, and
a dielectric material with a tunable refractive index around the plurality of optical structures of the metasurface,
wherein N optical structures of the metasurface are arranged in a tiled configuration with T tiles that each include M optical structures, where the M optical structures in each tile share a common control input, where M, T, and N are integer values with N=T*M; and
an active switch-matrix driver circuit integrated within the substrate to selectively apply a voltage pattern to the plurality of optical structures to control deflection of incident optical radiation according to a target deflection pattern, wherein the active switch-matrix driver circuit includes a plurality of driver channels that are each switched between a different subset of the tiles to allow for individual control of each tile.
15. The tunable optical device of claim 14 , wherein the active switch-matrix driver circuit comprises D driver channels to drive the N optical structures, with each driver channel switchable between a subset K of the T tiles, such that N=K*D, where D and K are integer values.
16. The tunable optical device of claim 14 , wherein the optical structures comprise metal optical structures.
17. The tunable optical device of claim 14 , wherein the optical structures comprise dielectric optical structures.
18. The tunable optical device of claim 14 , wherein each tile of optical structures comprises a one-dimensional array of elongated rails arranged parallel to one another with respect to an underlying optical reflector.
19. The tunable optical device of claim 14 , wherein each tile of optical structures comprises a two-dimensional array of pillars that extends from an underlying optical reflector.
20. The tunable optical device of claim 19 , wherein the pillars comprise one of: rectangular pillars, circular pillars, square pillars, and oval pillars.
21. The tunable optical device of claim 14 , wherein the dielectric material with the tunable refractive index comprises one or more of: liquid crystal, an electro-optic polymer, a chalcogenide glass, and a semiconductor material.
22. The tunable optical device of claim 14 , further comprising:
a diagnostic circuit integrated within the substrate to:
test an electrical characteristic of at least some of the optical structures,
identify an optical structure that is defective, and
disable at least the identified defective optical structure.
23. A tunable optical device, comprising:
a substrate;
a tunable optical metasurface comprising:
a plurality of metal optical structures on the substrate, and
a dielectric material with a tunable refractive index around the plurality of metal optical structures of the metasurface; and
an active switch-matrix driver circuit with a plurality of driver channels integrated within the substrate to selectively apply a voltage pattern to the plurality of metal optical structures to control deflection of incident optical radiation according to a target deflection pattern.