Updatable Holographic Diffraction of Monolithic Carbazole-Azobenzene Compound in Poly(methyl methacrylate) Matrix

The comprehensive mechanism of updatable holographic diffraction is presented for a monolithic compound of 3-[(4-nitrophenyl)­azo]-9H-carbazole-9-ethanol (NACzE) dispersed poly­(methyl methacrylate) film device. The maximum sensitivity occurs at 561 nm, which well coincides with an isosbestic point between cis-trans isomers of NACzE molecule. The holographic grating is ascribed to the absorption grating and the following refractive index grating due to the photo-orientation of NACzE molecules. The response and decay times for the diffraction are governed by the glass transition temperature of the matrix.