Enhanced photoinduced nematic reorientation in mixture with azo-dye-substituted polymer

The optically induced reorientation of nematic liquid crystal doped with azo-dye substituted polymer is investigated measuring photoinduced birefringence. These measurement reveal the value ((Delta) n approximately 0.1) of induced birefringence of liquid crystal with dye polymer which significantly exceeds the value of birefringence previously obtained in nematic mixture with the low molecular weight dye. More than one order of enhancement is connected with lower diffusivity of polymer. Applications for fiber all-optical switch and nonlinear filtering are suggested.