Homogeneous width of excitons in langmuir-blodgett films

Resonant Rayleigh scattering from a Langmuir-Blodgett monolayer of a cyanine dye has been studied. Particular attention has been paid to distinguish the resonantly enhanced Rayleigh scattering from that originating from surface roughness or inhomogeneity, which may cause spurious peak because of the coherent component included in them. A clear distinction has been made by measuring simultaneously the transmission/reflection spectrum at the Brewster angle. A homogeneous width has been extracted from the Rayleigh scattering data and found to be in qualitative agreement with a simple numerical calculation