光纤双折射对光纤环保偏能力影响的实验研究

Experimental investigation on the influence of optical fiber birefringence on the polarization maintaining ability of fiber coil

为了研究光纤双折射对陀螺光纤环保偏能力的影响,选用三种不同型号的光纤采用相同的绕制方法制作相同规格的光纤环。采用白光干涉仪测试光纤环的偏振耦合分布,并利用光纤环两端尾纤与白光干涉仪尾纤的熔点引起的偏振耦合干涉峰计算绕环光纤的双折射。通过不同光纤环测试结果的比较,分析绕环光纤双折射对光纤环保偏能力的影响。测试结果表明,三种绕环光纤的双折射分别为7.47×10^(-4)、6.36×10^(-4)、5.78×10^(-4),对应的三只光纤环的整体偏振耦合幅值分别为-74.79 dB、-70.06 dB、-64.97 dB。选取了相同对应位置的5个大耦合点进行偏振耦合幅值的统计,三只光纤环平均偏振耦合幅值分别为-57.85 dB、-49.85 dB、-44.49 dB。实验结果表明采用高双折射的保偏光纤有利于提高光纤环的整体保偏能力,且高双折射光纤具有较强的抵御外界应力影响的能力。

In order to investigate the influence of fiber birefringence on the polarization maintaining ability of fiber coil for gyroscope,three different types of optical fiber are selected and the same winding method is used to fabricate the same type fiber coil.The polarization coupling distribution of the fiber coil is measured by white light interferometer,and the birefringence of the coiled fiber is calculated by identifying coupling interference peak caused by the fusion point of the pigtail at both ends of the fiber coil and the white light interferometer.The influence of birefringence on the polarization maintaining ability of fiber is analyzed by comparing the test results of different fiber coils.The measurement results show that the birefringence of the three kinds of fiber coils are 7.47×10-4,6.36×10-4 and 5.78×10-4 respectively,and the whole polarization coupling amplitudes of the three fiber coils are-74.79 dB,-70.06 dB and-64.97 dB respectively.Five large coupling points at the same position are selected for statistic polarization coupling amplitude induced by external stress,and the average polarization coupling amplitude is-57.85 dB,-49.85 dB and-44.49 dB,respectively.The experimental results show that the high birefringence fiber can improve the whole plarization maintaining ability of the fiber coil,and the high birefringence fiber has a strong ability to resist the influence of external stress.