基于调谐滤波的光纤光栅解调技术研究

Demodulation Technology for Fiber Bragg Grating Sensors Based on Tunable Filtering

用宽带光源和自主研制的波长选择器IPD构成可调谐窄带光源,对测量光纤光栅阵列和参考光纤光栅进行波长扫描,借助光电探测器和DSP信号处理系统实现复用传感系统的解调。采用梳状滤波器进行波长校准,大大提高其检测精度。实验表明:该解调方案是可行的,且可获得较高的信噪比和测量精度,每个通道具有对15个以上FBG进行寻址解调的潜在能力。

Sensing fiber Bragg grating （FBG） array and reference FBG were scanned by a tunable narrow-band light source composed of a broad band source and a wavelength selector IPD manufactured by ourselves. The multiplexed sensing system was then demodulated by virtue of photo-detector and signal processing system. Its precision can be greatly improved by wavelength calibration with the comb-filter. Experiments demonstrate that this demodulation scheme is feasible and a higher signal-noise ratio and measuring accuracy can be acquired. Furthermore, a channel of this system has the potentiality of interrogating and modulating senor network with over fifteen FBGs.