Thermo-optic tuning of optical loss in an optical micro-ring resonator for reconfigurable photonics

Reconfigurable photonics is essential for next generation photonic signal processing and communication using photonic integrated circuits. The micro-ring resonator is an important building block in these systems. Conventional thermo-optic tuning used in photonic integrated circuits only tunes the resonant frequency, but not the quality factor and extinction ratio. Alternative methods such as electro-optic effect, all-optical effect, require complex fabrication and/or integration of foreign materials on conventional integrated-optic platforms such as silicon or silicon nitride. It is desirable to achieve full reconfigurability of the micro-ring resonator using the thermo-optic effect. We experimentally demonstrate this reconfigurability using a novel optical micro-ring resonator architecture. Thermo-optic tuning is used to tune the loss of the optical cavity, which leads to tuning of the quality factor (2000 to 10000) and extinction ratio (few dB to >30 dB). These devices are useful in reconfigurable switches and reconfigurable optical computing.