Wei Heming, Krishnaswamy Sridhar
Appl Opt. 2017 May 1;56(13):3867-3874. doi: 10.1364/AO.56.003867.
Fiber Bragg grating (FBG) dynamic strain sensors using both an erbium-based fiber ring laser configuration and a reflective semiconductor optical amplifier (RSOA)-based linear laser configuration are investigated theoretically and experimentally. Fiber laser models are first presented to analyze the output characteristics of both fiber laser configurations when the FBG sensor is subjected to dynamic strains at high frequencies. Due to differences in the transition times of erbium and the semiconductor (InP/InGaAsP), erbium-doped fiber amplifier (EDFA)- and RSOA-based fiber lasers exhibit different responses and regimes of stability when the FBG is subjected to dynamic strains. The responses of both systems are experimentally verified using an adaptive photorefractive two-wave mixing (TWM) spectral demodulation technique. The experimental results show that the RSOA-FBG fiber linear cavity laser is stable and can stably respond to dynamic strains at high frequencies. An example application using a multiplexed TWM interferometer to demodulate multiple FBG sensors is also discussed.
对采用基于铒的光纤环形激光器配置和基于反射半导体光放大器(RSOA)的线性激光器配置的光纤布拉格光栅(FBG)动态应变传感器进行了理论和实验研究。首先给出光纤激光器模型,以分析当FBG传感器在高频下受到动态应变时两种光纤激光器配置的输出特性。由于铒和半导体(InP/InGaAsP)跃迁时间的差异,当FBG受到动态应变时,掺铒光纤放大器(EDFA)和基于RSOA的光纤激光器表现出不同的响应和稳定状态。使用自适应光折变二波混频(TWM)光谱解调技术对两个系统的响应进行了实验验证。实验结果表明,RSOA-FBG光纤线性腔激光器是稳定的,能够稳定地响应高频动态应变。还讨论了使用复用TWM干涉仪解调多个FBG传感器的示例应用。