激光偏振特性对分光镜分光比影响的实验研究

Experiment Research for the Effect of Laser Polarization on Transmitting-Reflecting Ratio of Beam Splitter

在强度调制型光纤传感器的应用中,光源的功率波动是影响传感器精度的关键。采用分光镜设置参考光路的强度补偿技术虽然理论上可以实现高精度的补偿,但是由于分光镜分光比会因激光光源的偏振特性变化而改变。在分析光源偏振方向的变化对分光镜分光比影响的基础上,用仿真和系统实验进行了验证。理论及实验结果的吻合证明了分光比受光源偏振特性影响成周期性变化的结论。

In the application of intensity modulation type fiber optic sensor, the power fluctuation of a light source is a key factor affecting sensor accuracy. An intensity compensation technique which sets up a reference light path with a beam splitter can achieve high precision compensation in theory, but the light splitting ratio will be varied by the variations of the laser polarization. Based upon the analysis for the influence of the variation in light source polarization direction on light splitting ratio, the demonstration is carried out with simulation and system experiments. The theoretical and experimental results demonstrate the conclusion that the light splitting ratio is periodically varied with the influence of light source polarization.