Surface Relief Grating on Thin Film Containing Azobenzene-Polymer Material Linked by Hydrogen-Bonding

Abstract

Thin films of azobenzene-polymer material show unique photo-responsive behavior under irradiation with two interfering laser beams. That leads to generate surface inscription pattering known as Surface Relief Grating (SRG). Moreover, two different types of polymers were used in this research, and we used them with new series of azobenzene compounds. In fact, the H-bonding between donor and acceptor system was applied to create the link between the polymer and the azobenzene materials. The chromophore units in the azobenzene were attached to the polymer backbone through hydrogen bonding. In this research, we determined the efficiency of hydrogen bond to form SRG on azo-polymer thin films. The UV-VIS absorption spectra of the azo-polymer film showed broad band extending from 400-700 nm with maximum occurring at 430-580 nm. The laser’s wavelength was selected within the absorption band. Azo-polymer thin film was irradiated with a 532 nm green laser at room temperature. The obtained grating was confirmed by AFM scanning method, and grating depth up to 86 nm was observed.