Nanofabrication of high-Q thin film lithium niobate microrings using wet etching

As an excellent material platform for integrated photonics, thin film lithium niobate (TFLN) boots the performance of various integrated photonic devices such as integrated electro-optic modulators, integrated optical frequency combs, and nonlinear wavelength converters. The performance of these devices is highly dependent on the quality of nanofabrication method. Despite the fact that conventional inductively coupled plasma–reactive ion etching can achieve TFLN microrings with intrinsic quality factor (Q-factor) as high as 10 million, this method still shows high cost, poor reproducibility, and low throughput. Here, we achieved z-cut TFLN micro-racetrack with an intrinsic Q-factor over 11.9 million using we etching method. This method can facilitate the mass production of high-performance integrated TFLN devices with low cost, high reproducibility, and high throughput.