Fabrication of high-Q lithium niobate microresonators using femtosecond laser micromachining

Abstract

We report on fabrication of high-Q lithium niobate (LN) whispering-gallery-mode (WGM) microresonators suspended on silica pedestals by femtosecond laser direct writing followed by focused ion beam (FIB) milling. The micrometer-scale (diameter ~82 μm) LN resonator possesses a Q factor of ~2.5 × 10(5) around 1550 nm wavelength. The combination of femtosecond laser direct writing with FIB enables high-efficiency, high-precision nanofabrication of high-Q crystalline microresonators.