Coherence Loss in light backscattering by random media with nanoscale nonuniformities

An experimental technique for measuring time-resolved coherence loss and destruction of backscattered wavepackets in random media is described. The results of such measurements, performed with a modified Michelson interferometer, contain rich information about the characteristics of media nonuniformities. Experimental data for model nanosuspensions are compared with theoretical expressions developed in the article which include the effects of Mie-type resonant scattering. One such observed effect is attributed to enhanced inelastic optical transitions near the surface of nonmetallic nanoparticles. The inverse problem of characterization of multiscattering random media by backscattering is considered.