分布式光纤压力传感器的光信号处理

The Optical Signal Processing of Distributed Fiber Optical Force Sensors

在分析了来自传感光纤的微弱光信号的特点后，提出了一种带有声光调制器和偏振分光镜的马赫一泽德尔干涉仪来实现两正交偏振模的外差干涉。这种方法不仅消除了光源波动和背景光的影响，而且减小了信号处理中的损耗，提高了信噪比，得到了较高的测量精度。实验结果与理论分析得到较好的符合。

For the distributed fiber optical sen sor based on the principle of mede-coupling of polarization-maintaining fiber and the theory of partial coherence of quasi-monochromatic light,it is of great importance to process the weak optical signal from the sensing fiber.The characteristics of the optical slgnal was analyzed and suggestions were given for medified Mach-Zehnder interfer-ometer,which in cludes an acoustooptical medulator and a polarized-beam splitter to realize the het-erodyne in terferen ce. The method not only eliminates the influences of light source fluctuation and background light,but decreases the loss of the signal ptocessing,and improves S/N ratio.The experi-ment results coincide well with the analysis.