Wigner phase space distributions and optical coherence in turbid media
Smoothed Wigner phase space contours can be directly measured using a simple heterodyne detection-based optical system employing a He-Ne laser beam split into a 1 mW local oscillator and a 1 mW signal beam, and a spectrum analyzer for real time mean square beat amplitude measurement. Measured Wigner phase space distribution for 10 micron spheres in a water-glycerol mixture reveals a narrow diffraction component and a broad classical scattering with approximately equal cross sections. The momentum distribution of the scattered light agrees well with the Mie solution at low concentrations, but shows a narrow pedestal near the ballistic peak as well as a broader diffuse scattering contribution which disappears to the background as concentration increases.