High-Modulation-Depth Surface Relief Gratings Using s-s Polarization Configuration in Supramolecular Polymer-Azobenzene Complexes

The formation of the surface relief gratings (SRG) in azo-polymers strongly depends on the polarization configuration of the writing beams. So far the ss polarization configuration has been considered as ineffective in terms of SRG formation. Here, we report that very high-amplitude SRGs can be recorded when using the ss inscription geometry in supramolecular polymerazobenzene complexes and that the efficiency of the process strongly depends on the molecular weight of the polymer. Furthermore, a single holographic irradiation leads to the formation of the surface relief grating (primary grating) and, unexpectedly, to the formation of the secondary fine-structure grating with a considerable modulation depth in the direction perpendicular to the primary grating. The detailed analysis of holographic recording has been performed on the basis of the proposed phenomenological model. A new aspect of the phenomenon of the SRG formation has been indicated by demonstrating that the SRG can be inscribed for the ss polarization configuration. Since the SRG formation is considered as an important new tool in micro/nanofabrication technologies, both the formation of the SRG for ss geometry and the formation of the fine-structure grating open new possibilities in photonic applications.