Dynamics of cross-polarization-stimulated orientation scattering in a nematic liquid-crystal film

摘要

We have studied the dynamic evolution of stimulated cross-polarization scattering in a nematic liquid-crystal film. The effect is initiated by two-beam coupling between a cw incident polarized laser and its orthogonally polarized multifrequency noise components scattered by fluctuations in the director axis. Complex time- and intensity-dependent oscillations and energy exchanges among the pump and stimulated waves were observed. Imparting an ac modulation to the film further amplified the characteristic oscillations while it suppressed the background noise. The conditions for stimulated laser generation and the observed frequency spectra of the intensity oscillations are in good agreement with a quantitative theory that accounts for the temporal-spatial dependence of the wave mixing process. (c) 2005 Optical Society of America.