Spectral shifts as a signature of the onset of diffusion of broadband terahertz pulses.
We describe measurements of polarization dynamics as a probe of multiple scattering of photons in a random medium by use of single-cycle terahertz pulses. We measure the degree of polarization and correlate it directly with the single-scattering regime in the time domain. We also measure the evolution of the temporal phase of the radiation and show that the average spectral content depends on the state of polarization. In the case of broadband radiation, this effect can be used to distinguish photons that have been scattered a few times from those that are propagating diffusively.
Pearce
Jeremy
J
Department of Electrical and Computer Engineering, MS 366, Rice University, Houston, Texas 77251-1892, USA.
Jian
Zhongping
Z
Mittleman
Daniel M
DM