LNOI/Si3N4 heterogeneous integrated high-Q tunable microdisk resonator chip

In this paper, we demonstrate a high-Q LNOI microdisk coupling with a silicon nitride (Si₃N₄) optical waveguide. Its resonance characteristic can be turned by a thermistor on the microdisk resonator. The LNOI microdisk resonator is fabricated by inductively coupled plasma-reactive ion etching (ICP-RIE). Its sidewall is further smoothed by employing chemical mechanical polishing (CMP) to improve the quality factor (Q-factor). The LNOI/Si₃N₄ heterogeneous integrated resonator shows a Q-factor of 2.58 × 10⁵, and a wavelength tunability of ~14.5 pm/W.