All-optical phase shifter in silicon
View Patent ↗A device includes a semiconductor waveguide and a control signal waveguide formed along a planar surface of a substrate. The control signal waveguide includes a segment located along and proximate a segment of the semiconductor waveguide. The control signal waveguide is configured to photo-excite charge carriers in said semiconductor waveguide.
1. A device, comprising:
a substrate having a planar surface;
a semiconductor waveguide located along said planar surface; and
a control signal waveguide having a segment located along and proximate a segment of said semiconductor waveguide; and
wherein the control signal waveguide is configured to photo-excite charge carriers in said semiconductor waveguide.
2. The device of claim 1 , wherein said semiconductor waveguide comprises silicon.
3. The device of claim 1 , wherein said semiconductor waveguide includes an n-doped region and a p-doped region that form a semiconductor junction parallel to a propagation direction of said semiconductor waveguide.
4. The device of claim 3 , wherein said semiconductor waveguide includes an intrinsic region located between said n-doped region and said p-doped region.
5. The device of claim 3 , further comprising a power source connected to reverse-bias said semiconductor junction.
6. The device of claim 1 , wherein said control signal waveguide comprises silicon nitride.
7. The device of claim 1 , further comprising a vertical-cavity surface-emitting laser connected to inject light into said control signal waveguide, wherein the injected light has a short enough wavelength to cause inter-band excitations of charge carriers in the semiconductor waveguide.
8. The device of claim 1 , wherein said semiconductor waveguide is configured to provide an optical XOR function.
9. The device of claim 1 , wherein said semiconductor waveguide is a portion of a ring resonator.
10. A system, comprising:
a substrate having a surface;
a electrical control region along said surface of said substrate, the region including at least one electrical device being configured to produce an optical control signal; and
a second region of said substrate that is laterally separated from the electrical control region and includes at least one all-Optical device being configured to receive said optical control signal,
wherein said optical device includes:
a semiconductor waveguide located along the surface of the substrate; and
a control signal waveguide having a segment located along and proximate to a segment of said semiconductor waveguide; and
wherein the control signal waveguide is configured to photo-excite charge carriers within said semiconductor waveguide.
11. The system of claim 10 , further comprising and optical source configured to inject an RF-modulated laser signal into the control signal waveguide, the source having a wavelength less than about 1.1 μm.
12. The system of claim 10 , wherein said optical device includes an optical path with an index of refraction controlled by said optical control signal.
13. The system of claim 12 , wherein said optical path is a portion of a ring resonator or a Mach-Zehnder interferometer.
14. A method, comprising:
providing a semiconductor waveguide along a surface of a substrate, said semiconductor waveguide being formed from a semiconductor material having a bandgap energy;
forming a control signal waveguide located along and proximate to a segment of said semiconductor waveguide;
optically coupling said control signal waveguide to an optical source that is capable of producing an optical control signal at a wavelength that has an associated energy greater than the bandgap energy.
15. The method of claim 14 , wherein said semiconductor waveguide comprises silicon.
16. The method of claim 14 , further comprising forming a p-doped region and an n-doped region that forms a semiconductor junction parallel to a propagation direction of said semiconductor waveguide.
17. The method of claim 16 wherein said semiconductor waveguide includes an intrinsic region located between said n-doped region and said p-doped region.
18. The method of claim 16 , further comprising coupling said semiconductor junction to a power source configured to reverse-bias said semiconductor junction.
19. The method of claim 14 , wherein said control signal waveguide comprises silicon nitride.
20. The method of claim 14 , wherein said optical source is a vertical-cavity surface-emitting laser.