Aggregation induced convertible third-order nonlinear optical absorptions of the phenoxazinium containing films prepared by sol–gel method

Abstract The preparation and optical properties of phenoxazinium dye containing optical films by a sol–gel method are reported. The monomer of the phenoxazinium dye substituted with a hydroxyl group, prepared from 3-methoxyaniline by a five-step sequence, can be directly converted to the sol–gel precursor. The preparation and optical properties of phenoxazinium dye containing optical films are reported by in situ sol–gel spin coating with different mole ratios of the precursor to tetraethylorthosilicate. The UV–visible absorption spectra of the films were recorded and the dye aggregation phenomena were discussed. The third-order nonlinear optical properties of the films were measured by a picosecond Z-Scan method at 532 nm. The results indicate that the third-order nonlinear optical absorptions of the films are turned from the reverse saturation absorption with lower dye doping ratios to saturation absorption with higher doping ratios, which induced by the dye aggregation.