Zhang Jianhao, Wu Rongbo, Wang Min, Liang Youting, Zhou Junxia, Wu Miao, Fang Zhiwei, Chu Wei, Cheng Ya
State Key Laboratory of High Field Laser Physics and CAS Center for Excellence in Ultra-Intense Laser Science, Shanghai Institute of Optics and Fine Mechanics, Chinese Academy of Sciences, Shanghai 201800, China.
Center of Materials Science and Optoelectronics Engineering, University of Chinese Academy of Sciences, Beijing 100049, China.
Micromachines (Basel). 2021 Feb 25;12(3):235. doi: 10.3390/mi12030235.
We demonstrate the hybrid integration of a lithium niobate microring resonator with a silicon nitride waveguide in the vertical configuration to achieve efficient light coupling. The microring resonator is fabricated on a lithium niobate on insulator (LNOI) substrate using photolithography assisted chemo-mechanical etching (PLACE). A fused silica cladding layer is deposited on the LNOI ring resonator. The silicon nitride waveguide is further produced on the fused silica cladding layer by first fabricating a trench in the fused silica while using focused ion beam (FIB) etching for facilitating the evanescent coupling, followed by the formation of the silicon nitride waveguide on the bottom of the trench. The FIB etching ensures the required high positioning accuracy between the waveguide and ring resonator. We achieve Q-factors as high as 1.4 × 10 with the vertically integrated device.
我们展示了一种垂直配置的铌酸锂微环谐振器与氮化硅波导的混合集成，以实现高效的光耦合。微环谐振器是在绝缘体上铌酸锂（LNOI）衬底上使用光刻辅助化学机械蚀刻（PLACE）制造的。在LNOI环形谐振器上沉积一层熔融石英包层。通过首先在熔融石英中使用聚焦离子束（FIB）蚀刻制造一个沟槽以促进倏逝耦合，然后在沟槽底部形成氮化硅波导，在熔融石英包层上进一步制造氮化硅波导。FIB蚀刻确保了波导与环形谐振器之间所需的高定位精度。我们通过垂直集成器件实现了高达1.4×10的品质因数。
