Tuning on Optical Resonances of Microcavities Based on Thermal Dissipation Control

Optical resonances in a microcavity can be optically or thermally manipulated. Here, the tunings on optical resonances in silica microcavities with various dimensions are achieved by controlling the thermal dissipation with a thermal conductor. Finite-element thermal analyses show that the temperature in a mode volume of a microcavity can be definitely tuned, and the shifts of resonances near 1.55 μm are verified experimentally in a ~160-μm-diameter cavity. In addition, the slight resonance shifts in a ~450-μm-diameter cavity are examined indirectly from the output of single-mode Brillouin lasing. Compared to that of optical coupling, the thermal interaction space is much larger and fulfills a need to manipulate the high-quality resonances in a robust way.