Abstract

The first LiNbO₃ microtoroid resonators with high quality factor are produced by gravity-assisted surface tension reshaping. The original microdisk is produced by selective ion implantation and chemical etching. It is transformed into the microtoroid by thickening its rim through stretching the melted surface region by gravity force. The used thermal treatment process not only produces atom-scale smooth surface, but also enhances the optical confinement of the resonant modes. The resonant mode characteristics of the microtoroid resonators are calculated by the full-vectorial mode solver using the finite-element method and are used to explain the temperature tuning mechanisms. The 20-μm-diameter LiNbO₃ microtoroid has the intrinsic quality factor of 5.9 × 10⁴ and the tuning rate of 24.3 pm/°C. When the microtoroid temperature increases, the resonant wavelength shifts toward the long wavelength side. Numerical simulation results successfully confirm the action of thermo-optic effect and thermal expansion effect in the temperature tuning process. The high-Q LiNbO₃ microtoroid resonators facilitate the efficiency enhancement of nonlinear-optic devices.

© 2016 IEEE

High-quality LiNbO₃ microdisk resonators by undercut etching and surface tension reshaping

Tzyy-Jiann Wang, Jheng-Yu He, Cheng-An Lee, and Huan Niu
Opt. Express 20(27) 28119-28124 (2012)

High-Q inverted silica microtoroid resonators monolithically integrated into a silicon photonics platform

Jens Richter, Maziar P. Nezhad, Birgit Hadam, Thomas Taubner, Joachim Knoch, Florian Merget, Alvaro Moscoso-Mártir, and Jeremy Witzens
Opt. Express 26(21) 27418-27440 (2018)

High bandwidth on-chip capacitive tuning of microtoroid resonators

Christopher G. Baker, Christiaan Bekker, David L. McAuslan, Eoin Sheridan, and Warwick P. Bowen
Opt. Express 24(18) 20400-20412 (2016)

Free ultra-high-Q microtoroid: a tool for designing photonic devices

Mani Hossein-Zadeh and Kerry J. Vahala
Opt. Express 15(1) 166-175 (2007)

High-Q optical whispering gallery modes in elliptical LiNbO₃ resonant cavities

Makan Mohageg, Anatoliy Savchenkov, and Lute Maleki
Opt. Express 15(8) 4869-4875 (2007)