两种类型的光学电流传感头的灵敏度比较

Comparison of sensitivity between two types of optical current sensors

为了对块状和点式两种典型结构的传感头的灵敏度进行比较,采用矩阵光学的方法,对影响传感头灵敏度的诸因素如线性双折射、加工角差、正交反射间垂直小段的椭偏等进行了分析,推导了块状传感头中垂直小段的椭偏单独作用时对灵敏度影响的解析式,并对各因素同时作用时的灵敏度校正因子进行了定量仿真分析。结果表明,影响灵敏度最关键的因素是材料的线性双折射。单位长度内的线性双折射增加时,点式传感头灵敏度变化不大;且当其超过一定值时,点式具有比块状更高的灵敏度。

The sensitivity of a bulk type optical current sensor（OCS） was compared with that of a point type OCS. Based on Jones matrix,the factors affecting the bulk type OCS＇s sensitivity ,such as linear birefringence in horizontal path ,angle tolerance and elliptical polarization in vertical cantlet were analyzed and the effect of only elliptical polarization in vertical cantlet on the sensitiveity was deduced. When all the factors act together, a calibrating factor is necessary. This factor was simulated quantitatively. The comparison result shows that the linear birefringence existing in the material is the most important factor affecting the sensitivity and that the sensitivity of a point type OCS decrease little when linear birefringence of unit length increases. Even when it exceeds a specific value, the sensitivity of a point type can be greater than that of a bulk type.