Fluorescence Gratings from Chromophore-Functionalized Azo Molecule Migration

A Nile blue (NB) chromophore functionalized with disperse red 1 (DR1) was synthesized in three steps. NB-DR1-guest host-poly(methyl methacrylate) films were deposited on glass substrates and used to produce rewritable surface relief gratings (SRGs). These SRGs were observed by fluorescence microscopy after exposition of the films to an interference pattern from a laser, revealing the fluorescence pattern that mapped the angle-dependent SRG. The SRG formation was due to the azo-hauling chromophore migration under moderate irradiation conditions. Experiments with different host-guest concentrations showed that low doping of the host-guest system provides better contrast and a higher sensitivity of the fluorescence imaging to detect the surface grating. Finally, the chromophore-functionalized azo polymer material offers rewritable properties, which make it a potential candidate for applications in the field of data storage and holography.