Time-resolved optical phase space distributions for coherent backscatter

We explore enhanced backscatter from a random medium using time-resolved optical phase space measurement, i.e. measurement of joint position and momentum (x, p) distributions of the light field as a function of propagation time in the medium. Enhanced backscatter is a coherent effect and is not predicted by radiative transport theories. By using a low-coherence source in a heterodyne detection scheme, we observe enhanced backscattering resolved by path length in the random medium, effectively providing timing resolution. Such time-resolved studies are important for exploring the evolution of optical coherence as a function of penetration depth in the random medium. Optical phase space methods provide a visual as well as quantitative method of characterizing the spatial coherence properties and wavefront curvature of the input and scattered fields. These techniques may provide new venues for using optical coherence in medical imaging.

Duke Scholars

Author Adam P. Wax Biomedical Engineering