Laser Doppler velocimetry using a superheterodyne spectrum analyzer.
We present a superheterodyne optical spectrum analyzer where the frequency of the local oscillator changes linearly in time via an acoustooptic modulator. With this device we analyze the power spectrum of the light scattered by a rotating cylinder; a theoretical expression of the power spectrum shows that the spectrum width depends essentially on three different parameters: the angular velocity of the cylinder, the scattering angles, and the apparent linear dimensions of the illuminated area.
J
J
Leblond
el S E
el SE
Badawy