基于环状梯度折射率磁光玻璃的电流传感方法

An Optical Sensing Method of Current Based on Annular Graded-Index Magneto-Optical Glass

为消除块状光学玻璃型电流传感器中反射相移对测量精度的影响,提出了一种折射率呈梯度分布的环形磁光玻璃传感头结构。该环形磁光玻璃的内外两侧均为折射率渐变层,中间为折射率均匀层。同时,为便于信号光的输入输出耦合,该环形磁光玻璃上有一定大小的开口。理论分析表明,在一定条件下,光线在环形磁光玻璃中传播时,可不再与玻璃和空气界面接触,从而可以有效地避免反射相移的影响,提高传感器的测量精度。通过数值模拟分析了环形磁光玻璃的结构参数对光线传播轨迹以及有效初始角的影响。结果表明,通过合理设计环形磁光玻璃的结构参数,可以得到具有较大有效初始角且无反射相移的高灵敏度磁光玻璃型电流传感器。

We propose a novel optical element for bulk glass Faraday current sensor to avoid the influences of the reflection phase shift in traditional bulk glass current sensors.An annular graded-index magnetic-optic glass with an opening is designed as the sensing head,in which the inner and outer layers possess gradient indices,while the center layer is uniform.The theoretical analyses show that since the light propagating in the sensing head can not reach the interface between the magnetic glass and air,the reflection phase shift could be avoided essentially, resulting in dramatically enhancement of the sensitivity.The influences of the geometrical parameters on the beam traces and the effective range of the initial angle are numerically simulated.It is revealed that this sensing head with high sensitivity,large effective range of the initial angle and no reflection phase shift can be obtained by choosing proper parameters of the annular magnetic-optic glass.