对构成法布里珀罗腔(FP腔)的光纤布喇格光栅的传输特性进行了分析，推导了FP腔的光强透射率和反射率的解析表达式。将FP腔内一个光纤布拉格光栅的背面贴一压电陶瓷，通过给压电陶瓷施加扫描电压使透过FP腔的光的波长发生改变。光纤光栅受应力、应变及温度的影响时，其反射波长要发生相应变化，当探测器探测到最大光强时，根据给压电陶瓷施加的电压变化量就可确定布喇格光栅反射波长的移位量，测量精度可达到0.01nm。

Transmission characteristics of the fiber Bragg gratings composing FabryPerot(FP) cavity were analyzed, and the analytical expression of transmission and reflection of the light intensity of FP cavity was deduced. A piece of piezoelectric ceramic was posted on the back of one of the two fiber Bragg gratings, then the wavelength of transmitted light of FP cavity would change by applying a scanning voltage to the piezoelectric ceramic. When the fiber grating was effected by the stress, strain and temperature, its reflection wavelength changed correspondingly. When the detector detects the maximum intensity, the amount of wavelength shift of fiber Bragg grating can be determined by analyzing the variation of the voltage applied to the Piezoelectric ceramic, and the precision can reach to 0.01nm.