基于偏光干涉效应的低双折射光纤拍长测试方法

展示了一种低双折射光纤拍长测试方法。光路由ASE 光源、可调F-P 滤波器、两个线偏振器、待测光纤和相位补偿器组成。应用相位检测方法降低环境因素引入的误差,使用相位补偿器保证测试系统工作点位于光强对相位变化敏感处。搭建测试系统并进行了实际测量,系统检测可重复性良好。该方法对实验设备要求不高,对于待测光纤的长度没有限制,可测拍长范围达到20m,测量精度达1%。

Fiber beat-length measurement for low- birefringence fibers based on polarized light interference

A new method to measure the beat-length in low-birefringence fibers was shown. The optical path was consisted of an amplified spontaneous emission (ASE) light source, a fiber Fabry-Perot tunable filter, two linear polarizes, the measured fiber and a phase compensation plate. Phase detection was chosen to reduce the error from environment influence. Phase compensation plate was applied to ensure the testing system always sensitive to the change of phase. The testing system was set up and tested in reality. The system performed well in the repeated test. It is simple and has no strict demand on these equipments. There is no limitation on the configuration and the length of the measured fiber. It is reliable for fibers witch's beat-length is up to 20 m. The beat-length precision of the measurement is 1%.