双光纤Bragg光栅波长探测与解调技术

双光纤光栅可以用于光纤光栅传感器中波长移动的探测与解调,提出了一种新的解调方案并对几种可能的解调方案进行了实验对比。结果表明,在宽带光源光谱全功率较小的前提下,利用双光栅透射谱的相关及双光栅透射谱和反射谱的卷积都能实现波长移动的探测与解调,前者有更好的信噪比。而因为系统损耗过大,利用双光栅反射谱的相关不能探测与解调光栅中心反射波长的移动。双光栅波长探测与解调技术将波长的移动转化为相对光强极值的探测,避免了光纤光栅传感器中使用光谱仪等价格昂贵,体积庞大,使用不方便的光谱探测器件,有利于光纤光栅传感器的实用化。

Wavelength detection and demodulation technique with double fiber Bragg gratings

?A new scheme of wavelength detection and demodulation technique of FBG sensors with double fiber Bragg gratings is presented.The possible schemes of this technique are experimented and the results are compared.Both utilizing the convolution of transmission and reflecting spectrogram of two FBG and correlation of transmission spectrograms of two FBG can demodulate the shift of wavelength,and the latter has better SNR. But because the power of broadband light source is little and system wastage is large,utilizing the correlation of reflective spectrograms of sensing and demodulation FBG can't demodulate the shift of wavelength.Wavelength detection and demodulation technique of FBG sensors with double fiber Bragg gratings transforms the shift of wavelength into extremum detection of relative light and can replace those traditional spectrogram detection apparatus whose price is high,volume is large and using is not convenient.It can advance the practicality of FBG sensors.