Viscoplastic photoalignment modeling of asymmetric surface restructuring in azopolymer films by elliptically polarized light

Abstract

This study aims to test and validate the modern orientation approach of Saphiannikova et al. within the context of viscoplastic photoalignment (VPA) modeling. We focus on the formation of topographical structures under interference patterns featuring spatially varying elliptical polarization. By comparing our VPA modeling results with the asymmetric height profiles reported by Pagliusi et al., we observe a pronounced coupling effect between elliptically polarized light and the anisotropic orientation of azo-chromophores induced by this light. Our findings suggest that the photoinduced birefringent layer deviates the azimuth of elliptically polarized light, which in turn rotates the main axis of the anisotropic orientation in a chiral propagating structure. This self-induced rotation of light polarization influences the spatial dependence of interference profiles as a function of depth within the film. This research not only reinforces the importance of polymer backbone reorientation in azopolymer films but also enhances the predictive capabilities of VPA modeling in designing complex, light-driven topographical structures.