波长积累效应对光学玻璃电流传感器输出影响的理论分析

在单层保偏膜式光学玻璃电流传感系统中,费尔德(Verdet)常数、线性双折射和反射相移都是光波长的函数即存在色散特性,因此在采用宽带光源时系统中会产生波长积累效应。先给出了三者的色散特性公式,再对其波长积累效应进行理论分析和计算机仿真。研究结果表明,在所考虑的线性双折射和反射相移的量值范围内,波长积累效应对光学玻璃电流传感系统影响甚微,用单色光模型处理宽带系统的做法是合理的与可行的;光源谱宽变化对系统输出的影响小于0.025%,在考虑三者的联合影响时,Verdet常数色散的影响占主导地位,而且整体上系统输出随光源谱宽的增加而有微弱增加。

Theoretical analysis of the wavelength accumulation effect upon the output of a bulk-glass-material optical current sensor

In the system of bulk-glass-material optical current sensor that employed single-layer polarization-reservation-film,Verdet constant,linear birefringence and reflection-induced retardance all are the function of wavelength, i.e.they have dispersion features.Therefore,there will be wavelength accumulation effect in the systems employing broad-band optical sources.The dispersion formula of Verdet constant,linear birefringence and reflection-induced retardance inside a sensor head made of ZF-7 glass were given.Their wavelength accumulation effect upon an optical current sensor were theoretically analyzed and digitally simulated.The results show that the wavelength accumulation effect is less enough and the treatment of using monochromatic model to describe broad-band systems is reasonable and feasible,conditioned the value range of linear birefringence and reflection-induced retardance considered.The effect of the change of source spectral width on the output of the system is less than 0.025%.The effect of Verdet constant is dominant in the combined effect,and the system output is increased with the increase of the source spectral width.