Thermocapillary optical nonlinearity in stratified solutions

Optical nonlinearity caused by thermocapillary separation of the components of a stratifiable solution undergoing a phase transition in an inhomogeneous (periodic) temperature field was investigated. The dynamics of the separation of the components during formation of a diffraction grating, the diffraction efficiency, and the spatial resolution were studied as a function of the experimental conditions. Saturation of the diffraction efficiency was observed and this was interpreted on the basis of the dynamics of thermocapillary transfer of disperse-phase particles in a periodic temperature field.