光纤模斑谱复合材料固化传感器研究

本文报道了一种新型光纤传感器，其原理为通过测量光纤末端近场模斑谱来反映埋置在周围的树脂折射率的变化。计算了随着在树脂固化过程中折射率变化的功率谱密度分布，给出截止频率与折射率的近似关系。通过测量折射率匹配液，对传感器误差进行了估计。给出了利用这种传感器进行复合材料树脂固化监测的实验结果。发现这种光纤传感器的信号可以用来反映固化凝胶点和固化结束点。指出由于固化后光纤仍保持光波导特性，该光纤还可以用来监测受环境扰动的结构，如温度变化、振动等

Investigation of fiber optic speckle spatial spectrum(SSS) composite cure sensor

A new sort of fiber optic sensor was designed, the variation of refractive index of resin surrounding the embedded fiber optic was mean to observed by measuring the speckle spatial spectrum at the end face of the fiber optic. The normalized speckle spatial spectrum depended upon the variation of the refractive index occurred through the resin cure process was calculated, the approximate relation between refractive index and cutoff frequency was given. The instrumental error of the sensor was estimated through measuring to the refractive index matching liquid. The resin cure experiment results measured by the fiber optic sensor was given. This sort of fiber optic sensor was found to be able to detect the gel point and the end point of the cure process. For the fiber optic maintains wave guide performance after cure sensing, it was pointed that this sensor could also be used to sensing factors such as temperature and vibration which perturb the structures.