Features in coherent transmittance of a monolayer of particles

Coherent and incoherent transmittance values of a monolayer of particles ar e considered. Such a monolayer is a set of particles whose centers are loca ted in the same plane. We set forth the conditions for the effect of cohere nt-transmittance quenching, which takes place as a result of the interferen ce between incident and forward-scattered waves. Using the single-scatterin g approximation we determined size parameters and particle refractive index es for this interference effect in the case of identical isotropic spherica l particles. The influence of polydispersity and the fine structure of ligh t-scattering characteristics on the quenching effect has been estimated. It is shown that the polydispersity destroys this interference effect only at large widths of particle-size distribution functions. The influence of mul tiple scattering on this effect is considered in the quasi-crystalline appr oximation. Multiple scattering results in increasing size parameters and de creasing particle concentration at which coherent transmittance quenching t akes place in comparison with the case of single scattering. Our theoretica l results for suspensions of latex particles in water are in fairly good ag reement with the experimental results. (C) 2000 Optical Society of America [S0740-3232(00)01611-2] OCIS codes: 030.1670, 290.2200.