频移分离型三维激光多普勒测速仪研究

研究一种采用频移分离方法的新型三维激光多普勒测速仪（３ＤＬＤＶ）。该仪器以单色Ｈｅ－Ｎｅ激光器和单只光电探测器并配合简单的光学发射和接收系统即实现了三维速度分量的同时测量。三个分量的速度信号由声光调制器引入的三种光学频移区分，通过电子滤波器完成信号的相互分离。在光学发射系统设计中采用独特的单轴四光束结构，通过光束组合形成三双光束差动模式的激光多普勒测速仪光。本文中还给出了该仪器的系统设计参数并分析

Three-Dimensional Laser Doppler Velocimeter Using Frequency Shift Separation

A new three--dimensional laser Doppler velocimeter (3D LDV) by only using frequency shift separation method has been developed. Simultaneous measurementS of three velocity components are realized by a single color He-Ne laser and one photodetector with simple transmitting and receiving optics. The signals corresPOnding to different velocity components are distinguished by three different optical frequency shifts introduced by three Bragg cells, and separated by band--pass filters. A novel and simple fourbeam transmitting optics which contains three sets of dual--beam LDV systems is proposed, and the design specification of the 3D LDV system is presented. The measuring accuracy of the on--axis component is also discussed in this paper.