POLYMER-FILMS FOR 2ND-ORDER NONLINEAR OPT ICS

A new method is proposed to orient molecules in a polymer matrix and t o create non centrosymmetry which is necessary for second order non li near optical effects. This method which works at room temperature cons ists in putting the thin film simultaneously to a beam of visible and circularly polarized light which excites a class of molecules and to a static electric field (a few MV/cm) which orients this class of molec ules in a particular direction. It has been observed for thin films of polymethylmethacrylate, polystyrene, polyimide doped or functionalize d with the dye ''Disperse Red One'', or doped with photochroms like sp iropyrans.