This Engineering Research Equipment Grant will provide funds for a picosecond laser system (Nd:Yag, mode-locked, Q-switched 1.06um with second harmonic 0.53um capability 35ps pulses). The main objective is to expand the current NSF funded project on nonlinear processes in liquid crystals into the relatively unexplored picosecond regime where several new fundamental wave mixing processes of important applied potentials have been developed recently. Specially, theory and experiment have shown substantial beam amplication can be realized in any highly nonlinear Kerr media by two-wave interaction, owing to the generation of higher order diffracted waves. The effect has been experimentally demonstrated from the cw to the nanosecond regime in liquid crystals, organic polymers and semiconductors. Cavity-less optical logic gates and opto-optical modulation effects have also been recently demonstrated with nanosecond laser pulse. The picosecond laser system will enable study for the first time of the dynamics of these wave mixing processes, and the roles played by various semiconductor and organic material physical parameters such as recombinations, diffusions, excitonic formations, molecular orientations, corrections inter- and intra-band transitions, molecular sizes, electronic hyperpolarizability, etc. Several fundamental important effects and new nonlinear optical devices principals could emerge from this study.
