为实现S波段集成光波导放大器的高增益，以8 cm×6 cm尺寸的Tm3+掺杂锗酸盐玻璃为基片设计了S型，U型和F型弯曲结构波导。采用光束传播法(BPM)对弯曲波导进行损耗模拟，得到最优弯曲半径为1.90 cm时，损耗系数为0.04 dB/cm。在1482 nm波长处，F型波导的增益为13.01 dB，其值高于U型(8.21 dB)和S型(4.22 dB)波导，约是普通直波导(3.84 dB)的3倍。结果表明合理的光路设计(F型)可以大幅提高Tm3+掺杂锗酸盐玻璃平面光波导的光学增益。

To achieve high-gain S-band waveguide amplifiers with integrated configuration, S-, U-, and F-bend waveguides based on Tm3+-doped germanate glasses have been designed in an 8 cm×6 cm substrate. Using simulated-bend method, the optimal radius for the curved structure is offered to be 1.90 cm with loss coefficient of 0.04 dB/cm. For the F-bend waveguide, the internal gain at 1482 nm is derived to be 13.01 dB, which is higher than the values of 8.21 and 4.22 dB in the U-and S-bend waveguides, respectively, and nearly three times higher than that of the straight one (3.84 dB). Simulation results indicate that the reasonable optical path design can considerably enhance the optical gain in Tm3+-doped germanate glass channel waveguides.