COMPLEMENTARY GRATING EFFECT IN FORCED RAYLEIGH-SCATTERING

Abstract

The problem of non-single-exponential decay profiles of the forced Rayleigh scattering (FRS) is addressed by considering the contributions from complementary phase gratings. Since the technique relies on creating transient optical gratings by means of photolabels and reading the total diffraction signal intensity arising from the complementary gratings, a small difference in the decay time constants of optical fields derived from a complementary pair of such gratings could produce extremely nonexponential FRS decay profiles. By detailed simulation studies, we show how different profiles can be obtained with only minor differences in the decay constants, and how single-exponential analyses of such profiles can mislead in deducing the correct diffusion coefficients.