On-Chip Integrated Yb 3+ -Doped Waveguide Amplifiers on Thin Film Lithium Niobate

We report the fabrication and optical characterization of Yb 3+ -doped waveguide amplifiers (YDWA) on the thin film lithium niobate fabricated by photolithography assisted chemo-mechanical etching. The fabricated Yb 3+ -doped lithium niobate waveguides demonstrates low propagation loss of 0.13 dB/cm at 1030 nm and 0.1 dB/cm at 1060 nm. The internal net gain of 5 dB at 1030 nm and 8 dB at 1060 nm are measured on a 4.0 cm long waveguide pumped by 976 nm laser diodes, indicating the gain per unit length of 1.25 dB/cm at 1030 nm and 2 dB/cm at 1060 nm, respectively. The integrated Yb 3+ -doped lithium niobate waveguide amplifiers will benefit the development of a powerful gain platform and are expected to contribute to the high-density integration of thin film lithium niobate based photonic chip.

我们报道了采用光刻辅助化学机械刻蚀工艺制备的薄膜铌酸锂基掺镱（Yb³+）光波导放大器（YDWA）的制备与光学表征结果。所制备的掺镱铌酸锂光波导展现出低传输损耗特性：在1030 nm波长下传输损耗为0.13 dB/cm，1060 nm波长下为0.1 dB/cm。采用976 nm激光二极管泵浦的4.0 cm长光波导样品的测试结果显示，其在1030 nm波长下的内部净增益为5 dB，1060 nm波长下为8 dB；据此计算得到单位长度增益分别为1.25 dB/cm（1030 nm）与2 dB/cm（1060 nm）。该集成型掺镱铌酸锂光波导放大器将为高性能增益平台的发展提供助力，并有望推动基于薄膜铌酸锂的光子芯片高密度集成技术的进步。