High-yield and Reproducible Fabrication of High-Q Optical Micro-resonators on Thin-film Lithium Niobate

• Published in: Journal of physics. Conference series Vol. 2988; no. 1; pp. 12002 - 12008
• Main Authors: Shi, Haotian, Zhang, Tianheng, Zhang, Youwen, Zheng, Tiancheng, Nie, Changren, Liu, Chuanquan, Sun, Junqiang
• Format: Journal Article
• Language: English
• Published: Bristol IOP Publishing 01.03.2025
• Subjects: Acousto-optics; Acoustooptical devices; Fabrication yield; Lithium; Lithium niobates; Optical loss; Optical Micro-resonator; Optical waveguides; Optics; Q factors; Quantum optics; Resonators; Thin films; Thin-film Lithium Niobate
• ISSN: 1742-6588; 1742-6596
• DOI: 10.1088/1742-6596/2988/1/012002

Thin-film lithium niobate (TFLN) on insulator has emerged as an ideal platform for communication and quantum optics, making it a subject of extensive research. Previous studies have focused on monolithic electro-optic and acousto-optic devices on lithium niobate on insulator (LNOI) wafers. However, the fabrication process for achieving ultra-low loss TFLN devices remains challenging. Furthermore, there is insufficient research available regarding large-scale integration of TFLN photonic devices. Here, we propose and demonstrate a high-yield and reproducible fabrication process to characterize the high-Q micro-resonators (MRRs) on X-cut LNOI platform. By measuring the Q factors of MRRs, we can deduce the losses in TFLN optical waveguides and extract the yield accordingly. The fabricated MRR exhibits a lowest loss of 13.3 dB/m with a measured loaded Q factor of 1.5 million. Moreover, the majority of fabricated devices achieve losses below 20 dB/m with an impressive fabrication yield of 89.6%, showcasing advanced fabrication technology capabilities. This work establishes a foundation for large-scale monolithic integration of TFLN devices across various applications.