提出了一种测量光纤布拉格光栅的光-热效应的新方法，并利用它对一个实际的紫外写入光纤布拉格光栅的光-热效应进行了实验研究。利用980 nm半导体激光器作为抽运源、两个紫外写入光纤布拉格光栅作为反射镜、一段10 m长的掺铒光纤作为增益介质，构建了分布布拉格反射光纤激光器。通过合理设计，在分布布拉格反射光纤激光器工作的同时，获得了所使用的光纤布拉格光栅的反射光谱。实验结果显示，当抽运功率为100 mW时，光-热效应导致所使用的紫外写入光纤布拉格光栅的反射光谱向长波长方向漂移了0.034 nm。该方法可以很好地应用于光纤布拉格光栅的光-热效应的测量。

A novel method for measuring the photo-thermal effect of fiber Bragg gratings (FBGs) is presented. The photo-thermal effect of an UV-written FBG is studied by using the novel method. A distributed Bragg reflector (DBR) fiber laser is built up by using a 980-nm semiconductor laser as the pump laser, two UV-written FBGs as reflector and a 10-m-long Er-doped fiber as the gain medium. The reflection optical spectrum of the FBG used is obtained while the DBR fiber laser is working. The experimental result shows that the optical reflection spectrum of the FBG shifts by 0.034 nm towards longer wavelength when the pump power is 100 mW, which is induced by the photo-thermal effect. The novel method is applicable in measuring the photo-thermal effect of FBGs.