Abstract

In the vicinity of the phase transition temperature, approached from either the nematic of the isotropic phase, pulsed laser-induced individual and collective molecular recorientations, thermal and density fluctuations show interesting critical and dynamic effects. Using a transient dynamic grating technique, the magnitude of the nonlinearities and their rise- and decay-time dependences for both phases have been measured and analyzed by a quantitative nematogen theory. Unusually large and fairly fast nonlinear responses are observed and compared.

© 1991 Optical Society of America