On-chip tuning of the resonant wavelength in a high-Q microresonator integrated with a microheater

TL;DR

This paper demonstrates on-chip tuning of a high-Q microresonator's resonant wavelength using a microheater fabricated via femtosecond laser micromachining, achieving rapid and linear wavelength adjustments.

Contribution

It introduces a novel integrated microheater for microresonator tuning with fast response time and precise control, fabricated using femtosecond laser 3D micromachining.

Findings

Resonant wavelength tuning is linearly dependent on the square of the applied voltage.

The microresonator responds in less than 10 seconds, faster than conventional methods.

The microheater is effectively integrated and positioned about 200 microns from the resonator.

Abstract

We report on fabrication of a microtoroid resonator of high-quality (high-Q) factor integrated with an on-chip microheater. Both the microresonator and microheater are fabricated using femtosecond laser three-dimensional (3D) micromachining. The microheater, which is located about 200 micron away from the microresonator, has a footprint size of 200 micron by 400 micron. Tuning of the resonant wavelength in the microresonator has been achieved by varying the voltage applied on the microheater. The drifting of the resonant wavelength shows a linear dependence on the square of the voltage applied on the microheater. We found that the response time of the microresonator is less than 10 secs which is significantly shorter than the time required for reaching a thermal equilibrium on conventional heating instruments such as an external electric heater.