[OPTICAL REVIEW Vol. 6, No. 2 (1999) 104-109]

Enhanced Intensity Fluctuations of Multiply Scattered Light in Nonlinear Absorbing Media

Suguru SANGU,1 Takashi OKAMOTO,2 Jun UOZUMI1,* and Toshimitsu ASAKURA3

1Research Institute for Electronic Science, Hokkaido University, Sapporo, Hokkaido, 060-0812 Japan, 2Department of Control Engineering and Science, Kyushu Institute of Technology, Iizuka, Fukuoka, 820-8502 Japan, 3Faculty of Engineering, Hokkai-Gakuen University, Sapporo, Hokkaido, 064-0926 Japan

(Received November 28, 1998; Accepted January 8, 1999)

The properties of light transmission and interference phenomena in high dense media are investigated by means of numerical simulations in terms of nonlinear optical effect. Large intensity fluctuations are observed for nonlinear absorbing media, and do not agree with the fact that a decrease in absorption efficiency results in smaller intensity fluctuations for linear absorption media. From a variation in the speckle contrast it is found that the high-order path-crossing contributes to such intensity fluctuations. Moreover, the probability density of the total transmission changes from Gaussian statistics to log-normal ones for the small total transmission and to negative exponential ones for the large transmission, both of which appear in the strong localization regime. This indicates that the localization of optical waves might be controlled by the nonlinearity of the media.

Key words : intensity fluctuations, nonlinear absorption, path-crossing, non-Rayleigh statistics, localization, total transmission