在高功率光纤激光器中,增益光纤的热效应是限制激光功率提高的重要因素之一。传统的温度测量方法只能测量到增益光纤的表面温度,无法得到增益光纤内部不同位置的温度。采用分布式光频域反射(OFDR)技术测量全光纤放大器中增益光纤纤芯的温度。对采用OFDR技术得到的温度测量结果进行了标定,验证了OFDR测量工作状态下放大器内增益光纤温度的准确性。测量了输出功率为6 W的全光纤放大器内增益光纤纤芯的温度分布,测量结果与理论相吻合。这种测温方法为未来高功率光纤激光器的温度监测提供参考。 In high-power fiber lasers, the thermal effects of gain fibers are one of the important factors that limit the increase in laser power. The traditional temperature measurement method can only measure the surface temperature of the gain fiber and can not obtain the temperature of different positions inside the gain fiber. Distributed Optical Frequency Domain Reflectometry (OFDR) is used to measure the temperature of the gain fiber core in an all-fiber amplifier. The temperature measurement results obtained with OFDR technology were calibrated to verify the accuracy of the gain fiber temperature in the amplifier under OFDR measurement. The temperature distribution of the gain fiber core in an all-fiber amplifier with an output of 6 W was measured. The measured results are consistent with the theory. This temperature measurement method for the future high-power fiber laser temperature monitoring provide a reference.