非接触式光纤法珀微位移检测系统

An Non-Contact Fiber-Optic Fabry-Perot Detection System

设计一种采用双波长正交解调技术的光纤法珀检测系统,可用于微位移的检测.系统使用1×2密集波分复用器产生两路处于正交状态的输出信号,密集波分复用器的输出波长采用优化设计方法计算.信号处理采用arctan算法实现微位移信号的解调.实验通过对变化范围为0～0.8μm的位移进行检测,结果表明该传感系统的灵敏度达到0.468°/nm,非线性度仅为2.3%,可满足实际中微位移检测的需要.

A fiber-optic Fabry-Perot sensing system based on two-wavelengh quadrature-shifted demodulation technique is designed, which can detect the micro-displacement signal. An optical passive device, dense wavelength division multiplexer（DWDM）, is used to generate two quadrature phase-shifted output signals in the design scheme. The output wavelength of DWDM is calculated by the optimization design method. The signal of micro-displacement is then extracted using the arctan algorithm implemented digitally. The scheme test is implemented using Fabry-Perot cavity gauge length ranging from 0 to 0. 8μm. The result indicates that this sensing system has the potential to be used in the interrogation of micro-dis- placement signal with a sensitivity of 0. 468°/nm and the small nonlinearity of 2.3%.