用于微机电系统运动检测的激光差动多普勒技术

A Differential Laser Doppler System for MEMS Motion Measurements

提出了能够检测微机电系统器件面内瞬时运动的方法,建立了测量微机电系统谐振器面内运动速度和位移的差动激光多普勒系统。在光路中引入了电荷耦合器件监控系统,可以观察被测器件微小结构的调整和振动情况。使用信号处理电路从光电接收器输出的高频调制信号中分离出多普勒信号,并用时频分析算法从多普勒信号中提取出速度信息,再通过积分获得位移。测量了微机电系统谐振器的面内振动,测量结果的离散度误差为2.512μm。

A method to detect in--plane movement in the micro--electro--mechanical systems （MEMS） instantaneously was proposed. A differential laser Doppler system was set up to measure the in--plane velocity and displacement of the MEMS resonator. Utilizing CCD camera, the adjustment and vibration of the micro structures can he observed. The signal processing circuit was used to separate the Doppler signals from the high frequency demodulated outputs of the photo detector, and the time--frequency analysis was used to extract the velocity from the Doppler signals. By integrating the velocity, the displacement was obtained. The in--plane vibration of the MEMS resonator is measured, and the dispersion of the results is 2. 512μm.