Optical waveguide amplifiers based on NaYF₄ : Er${}^{3+}$, Yb${}^{3+}$ nanocrystals prepared by high-temperature thermal decomposition method with forward and backward pump schemes are designed. The gain characteristics of the two schemes are compared through simulation and experiment. For an input signal power of 0.1 mW and a pump power of 270 mW, relative gains of 5 and 5.6 dB are obtained by forward and backward pumping, respectively, in a 9-mm-long waveguide at a wavelength of 1530 nm. Simulation and experimental results show that the gain of backward pumping was higher than that of forward pumping by 12%. The utilization rate of pump light power is greatly improved, which is beneficial to the optimization design of waveguide amplifiers.

基于NaYF ₄：Er的光波导放大器${}^{3+}$，Yb${}^{3+}$设计了高温热分解法制备的纳米晶体，采用正向和反向泵浦方案。通过仿真和实验比较了两种方案的增益特性。对于0.1 mW的输入信号功率和270 mW的泵浦功率，通过在9mm长的波导中以1530 nm的波长分别进行正向和反向泵浦可获得相对增益5和5.6 dB。仿真和实验结果表明，后向泵浦的增益比前向泵浦的增益高12％。泵浦光功率的利用率大大提高，有利于波导放大器的优化设计。