用光纤激光器和阵列波导光栅搭建多通道自混合干涉系统,用光谱分析仪监测环路中的光谱特性。研究了多通道自混合干涉时的环路中光谱的特性以及温度对自混合干涉效应的影响。实验结果显示:环路中无光反馈时,其光谱是多个峰值,各峰值与阵列波导光栅通道特性对应,其包络与掺铒光纤激光器的自由增益谱吻合;有光反馈时,该通道光强减弱,多个通道同时引入光反馈时,光路中能量泄露到其他增益较高的通道,形成尖锋;当靶面距离光纤端面较近时,形成强反馈,该通道中会产生自激现象;当环境温度较高时,与AWG对应的各通道都能形成明显的波峰和波谷,温度较低时,波长较短部分波形较平坦,不适合作为传感通道。结果表明,多通道自混合干涉系统用于传感网络是可行的。

The spectra are detected by an optical spectrum analyzer (OSA). Spectral characteristics of multiplexing self-mixing interference (MSMI) signals and temperature influence to the gain of Er-doped fiber (EDF) are researched. A multiplexing system based on SMI is constructed with array waveguide grating (AWG) and fiber ring laser (FRL). Experiment results shows that without optical feedback in the ring, the spectrum has the same crests with AWG and the same trade with the liberal gain spectrums of EDF. When optical feedback is introduced to some channels, the powers in these channels get lower within moderate distance between the end of the fiber out from the channel and the target. When optical feedback is introduced to several channels, more energy will change to other channels and sharp peaks appear. When the target is too close to the end of fiber, self-oscillation will be formed. When the temperature is quite low the AWG cannot choose the center wavelength and suppress other wavelength in the channels at short wavelength part. Above all, the multiplexing system for sensing network is feasible.