Surface relief gratings from electrostatically layered azo dye films

Surface relief gratings (SRGs) were fabricated on composite films assembled by alternate electrostatic deposition of a polyelectrolyte, poly(dimethyld iallylammonium chloride), and an organic azo dye, congo red. The modulation of SRGs was found to increase with the thickness of the matrix films. Sign ificant photochemical bleaching of the azo dye in the polymeric microenviro nment as well as gradient-force-induced migration of the small azo dye cont ributes to the formation of the SRG structure. This finding demonstrates a facile method to fabricate SRGs for optical and information storage applica tions using commercially available azo dyes and polyelectrolytes. (C) 2000 American Institute of Physics. [S0003-6951(00)04922-6].