采用两级放大结构，利用光纤环形镜（FLM）并结合两根光纤光栅（FBG）进行增益平坦和增益控制，搭建了全光增益控制的增益平坦型高功率光纤放大器，实验测试了放大器的输出性能。放大器最大输出功率为1.399 W。在1535~1547 nm范围内，增益不平坦度为±0.75 dB。研究了信道在小功率和大功率信号输入条件下，放大器的增益控制特性，当信道2的功率在-33.7 dBm~-2.5 dBm和-14.8 dBm~16.4 dBm范围内变化时，剩余信道1的增益漂移范围可以分别达到0.04 dB和0.06 dB。

With the configuration of two-stage amplifying, the high power fiber amplifier with gain clamping and gain flattening is constructed. It makes gain flattened and gain clamped using fiber loop mirror (FLM) combined with two fiber Bragg gratings (FBGs). The output performance of the amplifier is tested, which shows that the maximum output power is 1.399 W and the gain fluctuation is reduced to ±0.75 dB in the range from 1535 nm to 1547 nm. Under the conditions of inputing small power and high power signals, the gain control characteristics of amplifier are researched, respectively. As the input power of channel 2 changing from -33.7 dBm to -2.5 dBm or -14.8 dBm to 16.4 dBm, the excursion ranges of channel 1 can be 0.04 dB and 0.06 dB, respectively.