提出了一种基于套嵌光纤光栅的光纤电流传感器,用二次曝光法制作的长周期光栅和 布拉格光栅套嵌而成的光纤光栅作为传感元件,在套嵌的光栅表面沉积一层高电阻镍铁合金作为 加热电极层。电流通过时对光栅区域加热,引起光栅光谱中心波长漂移,实现了高灵敏度的电流测量。 实验结果表明:所设计的光纤电流传感器电流响应灵敏度达到7.2×10-2 nm/mA, 且具有结构简单、体积小等优点,在高灵敏度的光纤电流检测领域具有广泛的应用价值。

A novel fiber-optic current sensor based on a nested fiber grating is proposed. Long period grating fabricated by two-exposure method and Bragg grating are nested to form fiber grating, and it’s used as sensing element. Surface of the nested fiber grating is sputtered with a layer of high resistance Ni-Fe alloy, which is used as heating electrode layer. When the current passes through, the grating region is heated, which leads to center wavelength of grating spectrum shifting. High sensitivity current measurement is realized. Experimental results show that the current response sensitivity of the designed optical fiber current sensor reaches 7.2×10-2 nm/mA. It has the advantages of simple structure, small size, and has wide application value in the field of high sensitivity optical fiber current detection.