Monolithic temperature-insensitive high- Q Ta 2 O 5 microdisk resonator

Abstract We demonstrate a temperature-insensitive high- Q tantalum oxide (Ta 2 O 5 ) microdisk resonator fabricated using electron-beam lithography and inductively coupled plasma reactive-ion etching. The microdisks exhibit a loaded Q -factor of 4.25 × 10 5 at 1,550 nm, which more than doubles (∼9.3 × 10 5 ) following thermal annealing at 600 °C. Remarkably, the temperature-dependent resonant wavelength shift is suppressed to less than 10 pm/°C across a broad 100 nm bandwidth. Furthermore, the resonators maintain high optical stability under elevated input powers, with no observed degradation in optical properties such as extinction ratio or Q -factor. The combination of high Q -factors and exceptional thermal stability positions the Ta 2 O 5 microdisk resonators as a promising platform for integrated photonic device applications, including on-chip narrow-linewidth lasers and precision sensing.