基于光纤M-Z干涉仪相干度变化的超窄线宽激光器跳模检测研究

Research on Mode Hopping Detection of Ultra-narrow Line-width Lasers Based on the Visibility Change of Fiber Mach-Zehnder Interferometer

摘要:

超窄线宽激光器随机发生的跳模现象,作为一种干扰或噪声,是降低光学相干检测系统性能的重要因素。为了有效检测单纵模超窄线宽激光器的模式稳定性,提出一种基于光纤M-Z干涉仪的超窄线宽激光器跳模检测方法,该方法通过在干涉仪内引入相位生成载波(PGC)外调制技术,将激光器跳模过程中光源相干性的变化转化为干涉仪相干度的突变,从而实现对整个跳模过程的实时监测。实验结果表明,该方法在检测灵敏度上有明显优势,能够有效监测跳模的持续时间、模式竞争随时间演化的动态过程等跳模细节,尤其适合用于短直腔激光器的跳模检测,并且能为光纤激光器跳模现象的预测与主动抑制提供重要参考。

Abstract:

As one type of disturbance or noise,random mode hopping of ultra-narrow line-width lasers is a significant factor that debases the performance of optical coherence detection system.In order to detect the mode stability characteristics of single-longitudinal-mode lasers with ultra-narrow line-width,a new method for detecting mode hopping based on fiber Mach-Zehnder interferometer with externally modulated phase generated carrier(PGC) is proposed.It transforms the entire mode hopping process to the visibility...