Lithium niobate microring with ultra-high Q factor above 108
Renhong Gao, Ni Yao, Jianglin Guan, Li Deng, Jintian Lin, Min Wang, Lingling Qiao, Wei Fang, Ya Cheng
Abstract
We demonstrate integrated lithium niobate (LN) microring resonators with Q factors close to the intrinsic material absorption limit of LN. The microrings are fabricated on pristine LN thin-film wafers thinned from LN bulk via chemo-mechanical etching without ion slicing and ion etching. A record-high Q factor up to 10 8 at the wavelength of 1550 nm is achieved because of the ultra-smooth interface of the microrings and the absence of ion-induced lattice damage, indicating an ultra-low waveguide propagation loss of 0.0034 dB=cm. The ultra-high Q microrings will pave the way for integrated quantum light source, frequency comb generation, and nonlinear optical processes.