[OPTICAL REVIEW Vol. 3, No. 1 (1996) 1-10]

Spectral Changes of Light and Scattering Phenomena

Tomohiro SHIRAI1 and Toshimitsu ASAKURA2

1Mechanical Engineering Laboratory, MITI, 1-2, Namiki, Tsukuba, 305 Japan, 2Research Institute for Electronic Science, Hokkaido University, Sapporo, 060 Japan

(Received October 9, 1995; Accepted November 21, 1995)

In the last few years renewed attention has been paid to the study of light scattering from random media. This is due to the recent discovery of a phenomenon that dynamic light scattering from a fluctuating random medium may produce shifts of spectral lines, even when the source and the scattering medium are at rest relative to the observer. It has also been demonstrated that a similar phenomenon may occur in static light scattering from spatially random media without dynamic fluctuations. By the well-known analogy between the processes of scattering and radiation, these phenomena in scattering are found to be closely related to the correlation-induced spectral changes in the coherence theory which are often referred to as the Wolf effect. In this paper some recent developments are reviewed on research regarding the phenomena of changes in the spectrum of light induced by scattering from random media. Emphasis is placed on a number of up-to-date attempts for elucidating the effects of multiple scattering on these phenomena.

Key words : spectral changes, Wolf effect, coherence theory, scattering theory, multiple scattering, random media, Rytov approximation, Born approximation