光源谱宽通过Verdet常量的色散对OCS输出影响的理论分析

Theoretical analysis of optical source spectral width on output of optical current sensor via Verdet constant dispersion

费尔德(Verdet)常量是衡量磁光玻璃材料性能的重要参数之一.它是光波长的函数,因而存在色散特性.当光学电流传感系统采用具有一定谱宽的光源时,会因材料的Verdet常量对不同波长的光具有不同的量值而对系统的输出产生影响.迄今为止对该问题的研究尚罕见报道.文中先求解了ZF-7玻璃Verdet常量色散特性公式中磁光系数的大小,然后对光源谱宽通过Verdet常量色散对输出的影响进行了理论分析和计算机仿真.研究结果表明,光源谱宽在60 nm范围内通过Verdet常量的色散特性对OCS系统输出的影响小于万分之四,因此在理论研究中若不考虑其他光学参量的色散效应,用单色光模型处理光源具有一定谱宽的系统的做法是合理的与可行的.此结果可供从事光学电流传感器研究的同行参考.

Verdet constant is a prominent parameter showing the property of magneto-optical glasses. Because it is the function of wavelength, it has dispersion features. Therefore, when broadband optical sources are used in optical current sensing systems, the Verdet constant will have a different value when the sensors work at a different wavelength. To overcome this situation, the value of the magneto-optic coefficient in the dispersion formula of Verdet constant of ZF-7 glass was calculated first, and then the effects of optical source spectrum width upon an optical current sensor via Verdet constant dispersion were theoretically analyzed and digitally simulated. The results show that the effect of the spectrum width on the output of an OCS is less than 0.01% in the wavelength range within 60 nm. Therefore, the treatment of using monochromatic model to describe broadband systems is reasonable and feasible, if the other optical parametersr dispersion of the sensing head are not considered. The results provide a possible reference for further research in the optical current sensing techniques area.