Photoinduced dichroism in dye-doped hybrid sol–gel films

Photoinduced dichroism measurements have been performed in hybrid silica-based sol–gel films containing Carbazole units, 2,4,7-trinitro-9-fluorenone (TNF) and Disperse Red 1 (DR1) at different concentrations. The dynamics of the parallel and perpendicular absorbances gives information on the azo-dye orientation under illumination and suggests that the dominant mechanism for the photoinduced anisotropy is the angular redistribution of the DR1 trans-molecules. Recording, storage and erasure, have been demonstrated for writing and reading light at 488 nm.