Opto-electronic modulator utilizing one or more heating elements
Described herein are methods, systems, and apparatuses to utilize an electro-optic modulator including one or more heating elements. The modulator can utilize one or more heating elements to control an absorption or phase shift of the modulated optical signal. At least the active region of the modulator and the one or more heating elements of the modulator are included in a thermal isolation region comprising a low thermal conductivity to thermally isolate the active region and the one or more heating elements from a substrate of the PIC.
1. A method for modulating light in a modulator circuit, the method comprising:
guiding light through an active region of a waveguide in the modulator circuit;
generating an electric field in the active region using a plurality of electrodes of the modulator circuit;
providing a bias voltage to the active region to adjust an absorption of the light by the modulator;
applying an initial level of heat to the active region using a heater of the modulator circuit; and
in response to an ambient temperature change changing the temperature of the modulator circuit, reducing heat applied by the heater to the active region from the initial level of heat to a reduced level of heat while maintaining the bias voltage provided to the active region, the reduced level of heat being lower than the initial level of heat.
2. The method of claim 1 , wherein the ambient temperature change changes the temperature of the modulator circuit to a higher temperature, and the heater reduces heat applied to the active region to the reduced level of heat in response to the higher temperature.
3. The method of claim 2 , further comprising:
in response to the ambient temperature change further changing the temperature of the modulator circuit, lowering the bias voltage while controlling the heater to reduce heat applied to the active region to the reduced level.
4. The method of claim 3 , wherein the ambient temperature change further changes the higher temperature of the modulator circuit to additional higher temperature that is greater than the higher temperature, and the bias voltage is lowered in response to the additional higher temperature of the modulator circuit.
5. The method of claim 2 , wherein the electric field is a time-varying electric field generated by a time-varying voltage that includes the bias voltage.
6. The method of claim 5 , wherein the time-varying voltage includes a rapidly-varying component superimposed on the bias voltage.
7. The method of claim 1 , wherein adding heat to the active region causes a variation in a refractive index of the active region.
8. The method of claim 7 , wherein adding heat to the active region causes the variation in the refractive index of the active region and a corresponding variation in an optical path traversed by the light in the waveguide.
9. The method of claim 1 , wherein the plurality of electrodes are positioned proximate to the active region, and the electric field causes a variation in a refractive index of the active region.
10. The method of claim 9 , wherein the electric field causes the variation in the refractive index of the active region and a corresponding further variation in an optical path traversed by light in the waveguide.
11. The method of claim 1 , wherein the ambient temperature change changes the temperature to a higher temperature that exceeds a threshold, and the heater is disabled to reduce heat applied to the active region from the initial level of heat to the reduced level of heat.