光纤菲佐应变传感器的波分频分复用方法

将波分复用技术与空间频率复用技术相结合,提出了新的光纤菲佐应变传感器波分频分复用方法:在粗波分复用(CWDM)的不同波段实现具有不同腔长的光纤菲佐应变传感器的空间频率复用。描述了基于该方法的光纤菲佐应变传感器复用系统的结构、原理及实验结果,讨论了复用技术中可能产生的串扰的影响及其解决方法。实验结果表明,该方法大大提高了光纤菲佐应变传感器的复用能力,可复用40个以上的菲佐应变传感器,且其应变测量精度达±5με,可满足实际应用的要求。

SFDM/CWDM of Fiber-Optic Fizeau Strain Sensors

A novel method for a large number of multiplexing fiber-optic Fizeau sensors using coarse wavelength division multiplexing (CWDM) and spatial-frequency division multiplexing (SFDM) is proposed and demonstrated. A CWDM device is used to multiplex signals from different sensor channels occupying different wavelength regions divided by the CWDM. The structure and principle of multiplexing fiber-optic Fizeau sensor are described, and the effect and reduction of cross-talk resulted from the multiplexing are analyzed. More than 10 Fizeau sensors arranged in a single channel can be multiplexed by using SFDM due to the long cavity length of the Fizeau sensor. The experimental results show that a strain accuracy of 5 με is achieved. There is little cross-talk between adjacent CWDM channels and also between two adjacent Fizeau strain sensors with certain cavity length difference. This system improves the multiplexing capability of Fizeau strain sensors significantly. It is anticipated that such a sensor system could find important applications in smart materials and health monitoring for large structures.