Orloff K L, Logan S E
Appl Opt. 1973 Oct 1;12(10):2477-81. doi: 10.1364/AO.12.002477.
A confocal backscatter laser Doppler velocimeter (LDV) that measures two velocity components has been developed. This device requires only two incident beams polarized normally to one another. Moreover, the velocity components sensed are nearly orthogonal. The velocimeter employs a combined dual-scatter, local oscillator arrangement to obtain the bidirectional sensitivity. Two photodetectors are used, each sensing only one Doppler frequency proportional to one of the very nearly orthogonal velocity components. In addition, a single Bragg cell serves to frequency bias both velocity components in order to eliminate directional ambiguity. A differencing technique has also been incorporated to enhance the dual-scatter Doppler signal corresponding to the transverse velocity.
一种测量两个速度分量的共焦背散射激光多普勒测速仪（LDV）已被开发出来。该设备仅需要两个相互垂直偏振的入射光束。此外，所感测的速度分量几乎是正交的。该测速仪采用组合双散射、本地振荡器配置来获得双向灵敏度。使用了两个光电探测器，每个探测器仅感测与非常接近正交的速度分量之一成比例的一个多普勒频率。此外，单个布拉格盒用于对两个速度分量进行频率偏置，以消除方向模糊性。还采用了一种差分技术来增强与横向速度对应的双散射多普勒信号。
