Transient gratings in azo-dye-doped poly(methyl methacrylate) polymeric films

Transient diffraction gratings in poly(methyl methacrylate) films doped with an azo dye Disperse Red 13 (DR13) are reported. The recording mechanism performed by laser light within the dye absorption range (514 nm) is due to photo-induced anisotropy in which light-induced repeated trans-cis photo-isomerization of DR13 molecules leads to quasi-stable molecular reorientation. The characteristics of transient gratings recorded by two mutually parallel polarized beams (PP and SS) as well as orthogonal linearly polarized beams (PS and +/-45degrees) were measured by monitoring the first-order diffraction intensity of the readout He-Ne laser beam. Furthermore, the potential application of such kinds of transient gratings in an all-optical switch is described.