偏振态调制的消偏振衰落干涉型光纤传感器

针对低双折射光纤双束干涉型传感器两行偏振态随机变化引起的信号衰落，提出了一种新型干涉型光纤传感器的消偏振衰落方案。通过在光纤干涉仪的输出端加对光波偏振态适当的高频调制．可以使干涉信号幅度波动小于４．７ｄＢ或６．３ｄＢ（与调制信号的形式有关），通过自动增益控制电路或将输出信号除以可见度的方式，能够在信噪比有所降低的情况下消除偏振衰落的影响，实现干涉型光纤传感器的消偏振衰落。

Modulated Polarization-induced Fading Eliminated Interferometric Fiber-optic Sensor

A new method to overcome the Pplarization- induced fading (PIF) in theconventional low-bireftingence optical fiber constructed interferometric sensor is proposed.By adding high-frequency modulation to the state of Polarization in the output arm of aninterferometer, the maximum PIF variation in the sensing signal is 4. 7 dB or 6. 3 dB(depending on the choice of maculation model). By either adding an electronicallyautomatic gain control circuit or dividing the signal by the interferometer' S visibility, thesignal fading is recovered at the expense of a relevant degradation of the signal/noise ratio(SNR)