Integrated wavelength selector
Integrated wavelength selectors are described. The wavelength selector may include silicon nitride ring resonator disposed vertically between a heater and a temperature sensor. The temperature sensor may be formed of silicon in some embodiments. The wavelength selector may be coupled to the output port of a tunable laser, or may be disposed within a laser cavity.
1. An integrated wavelength selector, comprising:
a substrate;
an integrated heater on the substrate;
an integrated silicon temperature sensor on the substrate; and
a ring waveguide of a first material disposed vertically between the integrated heater and the integrated silicon temperature sensor, the first material exhibiting a lower temperature coefficient of resonant frequency (TCF) than silicon.
2. The integrated wavelength selector of claim 1 , wherein the integrated heater is a ring substantially overlying the ring waveguide of the first material.
3. The integrated wavelength selector of claim 1 , wherein the first material comprises silicon nitride.
4. The integrated wavelength selector of claim 1 , wherein the integrated silicon temperature sensor is a p-n diode ring.
5. The integrated wavelength selector of claim 1 , wherein the integrated wavelength selector is disposed in a cavity of a tunable laser.
6. The integrated wavelength selector of claim 5 , further comprising a plurality of integrated heaters, integrated silicon temperature sensors, and ring waveguides disposed in the cavity of the tunable laser.
7. The integrated wavelength selector of claim 1 , wherein the integrated wavelength selector is coupled to an output of a laser and configured as a wavelength locker.
8. The integrated wavelength selector of claim 1 , further comprising a plurality of temperature isolation trenches disposed inside and outside the integrated silicon temperature sensor.
9. The integrated wavelength selector of claim 1 , wherein the first material is silicon nitride, and wherein the ring waveguide has a larger radius than the integrated silicon temperature sensor.
10. The integrated wavelength selector of claim 1 , wherein the first material is silicon nitride, and wherein the integrated wavelength selector further comprises first and second waveguides disposed on opposite sides of the ring waveguide.
11. A tunable wavelength selector, comprising:
a micro-heater;
a micro-temperature sensor formed of silicon; and
an optical filter of a first material disposed vertically between the micro-heater and the micro-temperature sensor, the first material exhibiting a lower temperature coefficient of resonant frequency (TCF) than silicon.
12. The tunable wavelength selector of claim 11 , wherein the micro-heater is ring-shaped and configured to substantially overlie the optical filter.
13. The tunable wavelength selector of claim 11 , wherein the first material comprises silicon nitride.
14. The tunable wavelength selector of claim 11 , wherein the micro-temperature sensor is a p-n diode ring.
15. An apparatus, comprising a tunable laser having a laser cavity, and the tunable wavelength selector of claim 11 disposed within the laser cavity.
16. The apparatus of claim 15 , comprising a plurality of ring resonators disposed within the laser cavity.
17. An apparatus, comprising a tunable laser and the tunable wavelength selector of claim 11 coupled to an output of the tunable laser.
18. The tunable wavelength selector of claim 11 , further comprising a plurality of temperature isolation trenches disposed inside and outside the micro-temperature sensor.
19. The tunable wavelength selector of claim 11 , wherein the first material is silicon nitride, the optical filter is a ring resonator, and wherein the ring resonator has a larger radius than the micro-temperature sensor.
20. The tunable wavelength selector of claim 11 , wherein the first material is silicon nitride, and wherein the optical filter comprises first and second waveguides disposed on opposite sides of a ring waveguide.