Biphotonic Z-scan studies of the nonlinear optical effects in azo-dye doped liquid crystal films

The nonlinear optical effects of azo-dye-doped liquid crystals are investigated using biphotonic Z-scan technique. The effects measured using the red light Z-scan can be modulated/switched with the simultaneous application of a green light Similar results can be using the green light Z-scan with a red light simultaneously. In the former case, the nonlinear properties are dominated mainly by thermal effects, while the effects are resulted from the molecular reorientation of liquid crystal induced by photoisomerized dyes in the latter one.