基于单个光纤光栅的Sagnac干涉仪的理论与实验研究

THEORETICAL AND EXPERIMENTAL INVESTIGATIONS ON SAGNAC INTERFEROMETER BASED ON SINGLE OPTICAL FIBER GRATING

提出了一种结构新颖的Sagnac干涉仪 ,分析计算了所含光纤光栅分别为均匀Bragg光栅和线性啁啾光栅时的透射响应 ,得到了均匀光栅Sagnac环的解析解 ,发现含均匀光栅时可得到间隔均匀的通带结构 ,而含啁啾光纤光栅时只能得到间隔非均匀的通带结构 .这两种结构都可能有应用价值 ,前者可用在密集波分复用系统中 ,后者可用在光纤传感领域中 .实验制作了两种通带间隔不同的、通带数分别为 8和 16的多通带滤波器 ,实验证实了理论计算得到的结果 .

A novel Sagnac interferometer employing an optical fiber grating in its loop is presented.The transmission responses of the loops with uniform Bragg gratings and linearly chirped fiber gratings are calculated. The analytic expressions for the loop with a uniform Bragg grating are given. It is found that the loop of a uniform grating leads to equally spaced band\|passes,while that of a chirped fiber grating leads to unequally spaced band\|passes. Such Sagnac loops may find applications in dense wavelength division multiplexing (DWDM) systems and optical fiber sensing. The multiple band\|passes filters with 8 and 16 channels are demonstrated experimentally. The experiments verify the results of our analysis.