啁啾光纤光栅法布里-珀罗传感器波分频分复用

SFDM/WDM for Large Number of Fiber-Optic F-P Sensors Based on Chirped Fiber Bragg Gratings

实现了一种具有大容量复用潜力的啁啾光纤光栅(CFBG)法布里-珀罗(F-P)传感器复用系统。该传感器复用系统的建立基于波分频分复用方法,即中心波长相同的传感器利用腔长不同空间频率不同来实现空间频分的复用,采用不同中心波长的传感器阵列与频分复用方法相结合就可实现波分频分复用。描述了该光纤光栅法布里-珀罗传感器复用系统的结构、原理及应变实验结果。实验结果表明,该方法可以大大地提高光纤光栅法布里-珀罗应变传感器的复用能力,理论上可复用数百个光纤光栅法布里-珀罗应变传感器;实验中应变测量精度好于±10με,可满足大部分实际应用的要求。

In this paper, a novel multiplexing system for fiber Bragg grating based Fabry Perot sensors （FBGFPs） is proposed, which is based on the wavelength division multiplexing （WDM） and spatial-frequency division multiplexing （SFDM）. For WDM, FBGFPs are arranged in different wavelength domains which are formed by a series of chirped FBGs with different central wavelengths. In the meanwhile, the sensors with different cavity lengths within the same wavelength domain can be multiplexed by using the SFDM method as they have different spatial frequencies resulted from different cavity lengths. Such a multiplexing system can improve the multiplexing capability of FBGFPs significantly, in principle hundreds of sensors could be multiplexed. The experimental results show that a strain accuracy of better than ±10με is achieved. There is little cross-talk observed between adjacent wavelength domains and also between any two adjacent FBGFPs with a certain cavity length difference.