光纤电流互感器传输模型的研究

Research of the Transmission Model of Fiber Optic Current Sensor

摘要: 目前，多数光学电流互感器的原理都是基于法拉第旋光效应，传感头作为传感器的关键器件，其线性双折射是限制光纤电流互感器大规模实用化的主要原因之一。由于线性双折射的互易性以及法拉第旋光效应的非互易性，采用正交反射镜能在补偿线性双折射的同时使法拉第效应加倍。文中利用密勒矩阵和斯托克斯矢量推导出正交反射镜与传统反射镜的等效传输矩阵，结果表明只有在电流为零时，线性双折射才能被正交反射镜补偿，当电流不为零时，线性双折射对正交反射式结构的影响低于直接反射式结构，实验同时表明，正交反射镜相比传统反射镜具有更好的振动免疫性。

Abstract: At present, most theory of optical fiber current sensor is based on Faraday effect. As the key com-ponents of OFCS, the linear birefringence of sensing head is one of the main reasons which res- tricts its wide-ranging applications. Due to the reciprocity of linear birefringence and non-recipro- city of Faraday effect, the usage of orthoconjugate mirror can eliminate the linear birefringence and double the faraday effect at the same time. We use Muller matrix and stokes vector to deduce the transmission matrix, which result that when current is null, linear birefringence can be eliminated; when current is not null, the impact of linear birefringence on orthoconjugate reflection structure is less than direct reflection structure. Meanwhile, experiments show that, orthoconjugate reflection structure has better vibration immunity than that of direct reflection structure.