Lithium niobate on insulator (LNOI), as an emerging and promising optical integration platform, faces shortages of on-chip active devices including lasers and amplifiers. Here, we report the fabrication of on-chip erbium-doped LNOI waveguide amplifiers based on electron beam lithography and inductively coupled plasma reactive ion etching. A net internal gain of ~30 dB/cm in the communication band was achieved in the fabricated waveguide amplifiers under the pump of a 974 nm continuous laser. This work develops new active devices on LNOI and may promote the development of LNOI integrated photonics.
Qiang Luo, Chen Yang, Zhenzhong Hao, Ru Zhang, Dahuai Zheng, Fang Bo, Yongfa Kong, Guoquan Zhang, Jingjun Xu. On-chip erbium-doped lithium niobate waveguide amplifiers [Invited][J]. Chinese Optics Letters, 2021, 19(6): 060008