Improvement of thermal properties in epitaxial aluminum nitride pedestal microring

We report thermal properties improvement of aluminum nitride (AlN) microring resonator by adopting epitaxial material and pedestal structure. With optimized inductively coupled plasma (ICP) dry etching using Cl2/BCl3/Ar mixture, pedestal microring resonators have been fabricated on epitaxial AlN. Transmission measurement reveals a loaded quality factor of ∼1×10⁴ at under-coupled condition, corresponding to a propagation loss of 27 dB/cm around 1.55 µm. Thermal effect induced resonant peak shift at different coupled powers is 6.3 pm/mW, and optical bistability can be observed at an input power above ∼115 mW.