采用波长可调谐光源与光时域反射技术(OTDR)结合的方案,通过对光脉冲调制技术和光电转换电路的优化,实现了一种对超弱全同反射光纤光栅的准分布式解调系统。实验中,20个中心波长相近的超弱反射光栅间隔2m放置于约5.8km长的光纤尾端,该解调系统成功实现了对这些反射率仅为0.01%的超弱反射光栅高信噪比的解调与定位,并且测得的光纤布拉格光栅(FBG)中心波长随温度变化的线性度达到99.7%以上。 By using a combination of wavelength-tunable light source and optical time-domain reflectometry (OTDR), a quasi-distributed demodulation system for ultra-weak and totally-reflecting fiber gratings is achieved through the optimization of optical pulse modulation and photoelectric conversion circuits . In this experiment, 20 ultra-weak reflection gratings with similar center wavelengths are placed at the fiber tail of about 5.8km at an interval of 2m. The demodulation system successfully achieves a high signal-to-noise ratio for ultra-weak reflection gratings with a reflectivity of only 0.01% And the linearity of the center wavelength of the FBG measured with the temperature is more than 99.7%.