Photofabrication of surface relief grating on films of azobenzene polymer with different dye functionalization

Photofabrication of surface relief grating (SRG) on very high-T-g and lower -T-g azobenzene functionalized polymers was investigated. Polymers with dif ferent degrees of functionalization were designed and synthesized to unders tand the chemical and physical intricacies involved at the molecular level in the photofabrication of SRG. The systematic study examined the influence of three important parameters: the degree of azo functionalization, the ir radiating light intensity, and the initial film thickness. From the experim ental results, we establish that the writing behavior of photofabricated SR G depends on the degree of azo functionalization. The effective critical in tensity of the irradiating light was found to be independent of the degree of functionalization. Threshold behavior for the deformation process as a f unction of the degree of functionalization was established. The observed fi lm thickness dependence of the SRG formation is discussed within the framew ork of existing fluid mechanics model. The thermal properties of the photof abricated SRG were also investigated.