利用白光干涉型光纤法一珀传感器和非扫描式相关解调原理,设计了一种基于非扫描式相关解调的多通道光纤法珀解调系统并进行了实验研究.利用柱面镜成线性光斑的特性以及2倍焦距成等大倒立像的原理,建立光纤法一珀非扫描式相关解调的光学模型,进行了光学特性分析和参量优化;设计了光学系统和硬件解调系统,制作了基于非扫描式相关解调的多通道光纤一法珀解调仪样机.同时采用巴特沃斯滤波器有效滤除了噪音,提高了仪器的解调准确度.测试实验表明:当测量范围为10~40μm,分辨率为8nm时,稳定性可达到7nm,能实现对传感器腔长的实时测量,且测量准确度高、稳定性和一致性好,能够进行多点探测,提高了复用能力.
A multi-channel optical fiber Fabry-Perot demodulation system based on non-scanning correlation demodulation combining with white light interfered Fabry-Perot sensor is designed. Utilizing cylindrical lens collecting and focusing light as linear light spot and get equivalent inverted image at 2 times focal length plane, the corresponding optical model is set up; the optical characteristic analysis and parameter optimization is carried on; and the optical system and embedded demodulation system is designed. A Butterworth filter is used to filter out the background noise on the correlation signal effectively. Experiments based on the prototype demodulator show that the stability is up to 7 nm, at the measuring range of 10-40μm, with the resolution of 8nm. The experimental results indicate that the system can achieve real-time measurement, high measurement accuracy, stability and consistency, and can realize multi-point detection and improve the multiplexing capacity.