Thermally modulated photonic switch and associated methods

1. A thermally modulated photonic switch, comprising:

a topology-optimized structure that includes dispersed silicon and silicon dioxide, wherein the topology-optimized structure includes an input waveguide, a first output waveguide, and a second output waveguide;

wherein:

the topology-optimized structure routes a light beam from the input waveguide to the first output waveguide, when the topology-optimized structure is at a first predetermined temperature that causes a refractive index of the silicon in the topology-optimized structure to assume a first predetermined value; and

the topology-optimized structure routes a light beam from the input waveguide to the second output waveguide, when the topology-optimized structure is at a second predetermined temperature that causes the refractive index of the silicon in the topology-optimized structure to assume a second predetermined value that is distinct from the first predetermined value.

2. The thermally modulated photonic switch of claim 1 , further comprising:

a buried thermal oxide layer disposed adjacent to and beneath the topology-optimized structure;

a silicon handle disposed adjacent to and beneath the buried thermal oxide layer;

a first oxide cladding layer adjacent to and on top of the buried thermal oxide layer, the first oxide cladding layer covering the topology-optimized structure; and

a second oxide cladding layer disposed adjacent to and on top of the first oxide cladding layer, the second oxide cladding layer including a micro-heater and a routing layer.

3. The thermally modulated photonic switch of claim 2 , wherein the micro-heater is made of a titanium-tungsten alloy.

4. The thermally modulated photonic switch of claim 2 , wherein the micro-heater causes a temperature of the topology-optimized structure to change to one of the first predetermined temperature and the second predetermined temperature.

5. The thermally modulated photonic switch of claim 1 , wherein one of the first predetermined temperature and the second predetermined temperature is room temperature.

6. The thermally modulated photonic switch of claim 1 , wherein the light beam is infrared light.

7. The thermally modulated photonic switch of claim 6 , wherein the infrared light has a wavelength of 1550 nm.

8. The thermally modulated photonic switch of claim 1 , wherein the topology-optimized structure is produced by a computerized inverse-design process.

9. The thermally modulated photonic switch of claim 1 , wherein the topology-optimized structure has a width of less than 2.1 microns and a height of less than 4.1 microns.

10. A thermally modulated photonic switch, comprising:

a topology-optimized structure that includes dispersed silicon and silicon dioxide, wherein the topology-optimized structure includes an input waveguide and N output waveguides;

wherein the topology-optimized structure routes a light beam from the input waveguide to a particular one of the N output waveguides, when the topology-optimized structure is at a corresponding one of N distinct predetermined temperatures that causes a refractive index of the silicon in the topology-optimized structure to assume a corresponding one of N distinct predetermined values.

11. The thermally modulated photonic switch of claim 10 , wherein N is equal to 2.

12. The thermally modulated photonic switch of claim 10 , wherein N is equal to 3.

13. The thermally modulated photonic switch of claim 10 , further comprising:

a buried thermal oxide layer disposed adjacent to and beneath the topology-optimized structure;

a silicon handle disposed adjacent to and beneath the buried thermal oxide layer;

a first oxide cladding layer adjacent to and on top of the buried thermal oxide layer, the first oxide cladding layer covering the topology-optimized structure; and

a second oxide cladding layer disposed adjacent to and on top of the first oxide cladding layer, the second oxide cladding layer including a micro-heater and a routing layer.

14. The thermally modulated photonic switch of claim 13 , wherein the micro-heater causes a temperature of the topology-optimized structure to change to the corresponding one of the N distinct predetermined temperatures.

15. The thermally modulated photonic switch of claim 10 , wherein one of the N distinct predetermined temperatures is room temperature.

16. The thermally modulated photonic switch of claim 10 , wherein the topology-optimized structure is produced by a computerized inverse-design process.

17. The thermally modulated photonic switch of claim 10 , wherein the topology-optimized structure has a width of less than 2.1 microns and a height of less than 4.1 microns.

18. The thermally modulated photonic switch of claim 10 , wherein the thermally modulated photonic switch is one 1×N switching subunit among a plurality of alike 1×N switching subunits that are optically interconnected in a cascaded fashion to form a 1×M photonic switch having k stages and N k outputs.

19. A method of thermally modulated photonic switching, the method comprising:

inputting a light beam to an input waveguide of a topology-optimized structure that includes dispersed silicon and silicon dioxide, wherein the topology-optimized structure includes N output waveguides; and

routing the light beam from the input waveguide to a particular one of the N output waveguides by adjusting a temperature of the topology-optimized structure to a corresponding one of N distinct predetermined temperatures that causes a refractive index of the silicon in the topology-optimized structure to assume a corresponding one of N distinct predetermined values.

20. The method of claim 19 , further comprising optically interconnecting, in a cascaded fashion, a plurality of alike 1×N switching subunits to form a 1×M photonic switch having k stages and N k outputs, wherein the topology-optimized structure forms a part of a particular 1×N switching subunit in the plurality of alike 1×N switching subunits.