High-Q integrated lithium tantalate microring resonators for on-chip comb generation
Jiachen Cai, Pi‐Yu Wang, Jin Li, BoWen Chen, Liping Zhou, Xinjian Ke, Bingcheng Yang, Ailun Yi, Chengli Wang, Jiaxiang Zhang, Chun‐Hua Dong, Shuai Wan, Xin Ou
Abstract
Lithium tantalate on insulator (LTOI), taking advantage of high cost-effectiveness, ultra-low optical loss, and prominent electro-optic (EO) coefficient, shows great potential as an integrated waveguide-based optical platform for commercialization. Further research on monolithic nonlinear source generators with tunable features is crucial in its early stages. Here, we fabricate low-loss microring resonators (intrinsic Q value above 4 × 10 6 ) via universal subtractive manufacturing. Both Kerr and EO combs are realized based on X-cut LTOI high-Q resonators. Specifically, we elucidate the complicated synergy caused by a photorefractive (PR) effect and thermo-optic modulation, observing the soliton step using the facile laser scanning technique. Furthermore, the preliminary experimental result of the static EO comb is also exploited in a 20 GHz free spectral range (FSR) LTOI microring resonator, verifying the versatility of this unique photonic platform for on-chip microcomb generation.