温度和振动对光纤马赫-曾德干涉仪的影响与动态补偿研究

环境温度变化和振动会引起光纤马赫-曾德干涉仪两臂相差随机性变化,致使干涉仪输出不稳定.本文研究了自然条件下外界温度和振动对基于3×3耦合器干涉仪的影响,分析结果表明,温度和振动所引起的干扰主要集中于100 Hz以下的低频成分中.为了消除这些干扰,设计了单臂补偿的反馈回路以稳定输出信号,并提出了一种利用象限判决方法来区分反馈正负性的动态补偿方法.实验中利用3×3耦合器3个输出端中其中2个进行光电变换、差分放大等反馈电路后驱动管状压电陶瓷,使缠绕在其上的光纤伸缩,动态补偿干涉仪相差的漂移,稳定干涉仪输出即3×3耦合器第三输出端口的信号.针对自然环境下温度和振动引起的干扰,本文研制了一种稳定的动态补偿装置,能有效抑制160 Hz以下的低频干扰,实时补偿干涉仪两臂的相差漂移,干涉仪输出稳定的干涉信号,波动幅度小于5.64%.

Effect of Temperature and Vibration on Optical Fiber Mach-Zehnder Interferometer and Dynamic Compensation

Environment temperature changes and vibration will cause the random change of phase difference between two arms in the Mach-Zehnder interferometer (MZI), resulting in the instability of interferometer outputs. In this paper, the effect of temperature and vibration on the 3?3 coupler-based interferometer was studied in detail under natural conditions. Results show that the interference frequency caused by temperature and vibration is mainly concentrated in the low frequency section below 100 Hz. In order to eliminate these disturbances, a single-arm compensation feedback loop was designed to stabilize the output signal, and a dynamic compensation method was proposed based on quadrant judgment for distinguishment of positive and negative feedback. In the experiments, two of the three outputs of the 3?3 coupler are transformed from optical single to electrical one, and drives the piezoelectric ceramic to stretch the fiber wound on it after differential amplifier and other feedback circuits, which dynamicly compensate the phase difference drift of the interferometer and stablize the output namely the third output of the 3?3 coupler. Considering the disturbances caused by the temperature and vibration under nature environment, a stable dynamic compensation device was successfully demonstrated which can effectively suppress low-frequency interference below 160 Hz, and compensate real-time the phase difference drift between two arms of the interferometer, while the output becomes stable with fluctuations less than 5.64%.