Abstract

Optical propagation is studied in samples of random close-packed polystyrene and titania spheres with indices of refraction n = 1.59 and n ≃ 2.8, respectively. Both spatial and temporal aspects of propagation are probed by measuring the transmission of light as a function of sample thickness as well as fluctuations in the transmitted light intensity as a function of laser frequency. Fluctuations in intensity with amplitude as large as the average intensity of light are observed within a single coherence area of a speckle pattern as the laser frequency is scanned. This makes clear the essential role of interference in transport and makes possible the measurement of the width of the distribution in the transit time of light through the sample.

© 1986 Optical Society of America