微振动的高精度测量  

High-accuracy micro-vibration detector

作　　者：俞本立[1] 孟军[1] 

机构地区：[1]安徽大学信息材料与器件重点实验室,安徽合肥230039

出　　处：《光电工程》2006年第1期120-122,136,共4页Opto-Electronic Engineering

基　　金：安徽省优秀青年科技基金资助课题(04042045)

摘　　要：为了测量振幅小于1μm的微振动信号,在传统迈克尔逊干涉仪的基础上,提出了一种大光程差情况下的实时高精度测量系统。该系统使用单频窄线宽光纤激光器来减小长光程差下的相位噪声影响;用零差解调方法来抑制环境影响导致的相位漂移;双路平衡检测的使用将光源强度噪声降低16dB左右。当测量距离为10m时,光源引起的相位噪声仅为5.28×10-rad/Hz1/2;但由于6电路处理上的限制,实际可探测的最小灵敏度约为10-rad/Hz1/2。当被测信号在100Hz^4kHz之间5时,系统具有良好的线性响应度。To measure micro-vibration signal with amplitude less than 1μm, a real-time, high accuracy detector based on traditional Machelson interferometer was proposed. A narrow-line width fiber laser was introduced to reduce phase noise under the condition of long optical path difference, and phase shift caused by environment can be suppressed with homodyne demodulation scheme. Intensity noise can be decreased by 16dB using balanced detection. When detected space is 10m away, phase noise caused by laser is only 5.28 × 10^-6 rad/Hz^1/2. Because of the circuit limit, detector sensitivity is only 10-5 rad/Hz^1/2. When detected signal ranges from 100Hz to 4KHz, the system has good linear response.

关 键 词：微振动测量 光纤激光器 零差解调 平衡检测 

分 类 号：TG801[金属学及工艺—公差测量技术]