激光多普勒离面振动测量的研究

Research on the Longitudinal Vibration Measurement with Laser Doppler Technology

提出了一种新型可辨向激光多普勒离面振动测试仪,计算并分析了激光多普勒技术的双相检测和矩形光栅的衍射光强分布。采用相位光栅作为光学混频器件,消除了信号的相互干扰,提高了测量的信噪比并充分的利用了光能。实验结果表明,该系统能有效地实现可辨向离面振动的测量,测量距离范围广,并可获得较高的精度。

A new difference laser Doppler longitudinal vibrometer with directional discrimination is introduced. Two-phase detecting technique used to distinguish the direction and the intensity distribution of the phase grating diffraction pattern is analyzed. The phase grating is a frequency-mixing device that can get high SNR signals. The experiments prove that the system can be used to measure longitudinal vibration and distinguish the direction of the moving object with a high accuracy.