Dändliker R, Iten P D
Appl Opt. 1974 Feb 1;13(2):286-90. doi: 10.1364/AO.13.000286.
The described system measures the flow velocity without directional ambiguity. It does not need an optical frequency offset. Polarized illumination beams and two optical detection channels with appropriate polarizing elements are used to determine the flow direction. The Doppler signals from the two channels are identical but have a phase offset that changes sign if the flow direction is reversed. The method has been verified experimentally for low and high concentrations of scattering particles.
所描述的系统能够在不存在方向模糊性的情况下测量流速。它不需要光学频率偏移。使用偏振照明光束以及带有适当偏振元件的两个光学检测通道来确定流动方向。来自两个通道的多普勒信号是相同的，但具有一个相位偏移，当流动方向反转时该相位偏移的符号会改变。该方法已针对低浓度和高浓度散射粒子进行了实验验证。
