干涉型光纤传感器阵列消PIF技术的研究

Study on Elimination of PIF in Interferometric Fiber Optic Sensor and Its Array

针对低双折射光纤双光束干涉型传感器两臂偏振态随机变化引起的信号衰落 ,提出了一种新型消偏振方式 ,它可以在可见度略有下降的情况下 ,较好地消除偏振态变化引起的干涉信号可见度的随机变化。该方案是通过相互正交的两个偏振态来补偿由于其中一个偏振态变化导致的干涉信号衰落。通过自动增益控制电路可以使传感信号稳定 ,能够在信噪比有所下降的情况下消除偏振衰落的影响 。

A new method using polarization switching for elimination of polarization induced signal fading(PIF) in interferometric sensor and its array is described. The visibility can be recovered by polarization switching that changes an orthogonal state of polarization(SOP) to an in pulse SOP.By adding an electronic automatic gain control circuit, the signal fading is recovered at the expense of somewhat of signal to noise ratio degradation.The application of the method in the interferometric array is introduced.