提出了一种对光纤布拉格光栅(FBG)在横向压力负载条件下的谐振波长分裂进行高灵敏检测的方案,并进行了实验研究。采用偏振分束器和偏振无关的光纤迈克耳逊干涉仪组成检测系统,利用相位调制技术,将光纤布拉格光栅的谐振波长分裂的检测转化为相位差的测量,从而大大提高光纤光栅横向压力负载传感的初始分辨率。利用该系统进行横向压力负载传感实验,得到0.025 N/mm横向负载初始分辨能力。

In this paper, a new scheme to measure the difference of two resonance wavelengths of a fiber Bragg grating (FBG) load sensor is presented. In order to acquire high primary resolution of the fiber grating transverse load sensing, a beam splitter and a Michelson interferometer with two Faraday rotation mirrors (FRM) are adopted to compose the detecting system, the instability caused by birefringence of the fibers in the interferometer is considerably reduced. This new FBG load senor is demonstrated and the primary resolution of 0.025 N/mm is obtained.