Surface Relief Gratings: experiments, physical scenarios and photoinduced (anomalous) dynamics of functionalized polymer chains

摘要

Surface Relief Gratings (SRG) were demonstrated experimentally more than 20 years ago. Despite many years of research efforts the underlying physical mechanisms remain unclear. In this paper we present a short overview of the main concepts related to SRG - photofluidization and its counterpart, the orientational approach - based on a seminal paper by Saphiannikova et al_1 Next, we summarize the derivation of the cos2 θ potential, following the lines of recent paper of this group._2 Those results validate the generic Monte Carlo model for the photoinduced build-up of the density and SRG gratings in a model polymer matrix functionalized with azo-dyes,_3 presented in another part of the paper. The characterization of the photoinduced motion of polymer chains, based on our recent paper,_4 is briefly discussed in the last part of the paper. This discussion offers a sound insight into the mechanisms responsible for inscription of SRG as well as for single functionalized nanoparticle studies.