Spontaneous formation of optically induced surface relief gratings

TL;DR

This paper presents a model combining diffusion and coupled mode theory to explain and predict the spontaneous formation of surface relief gratings in azopolymer thin films, aligning well with experimental observations.

Contribution

It introduces a novel combined theoretical framework to describe the self-organization and patterning process in azopolymer films.

Findings

The model accurately predicts surface relief profiles.

It explains the mechanism of spontaneous pattern formation.

Good agreement with experimental data.

Abstract

A model based on Fick's law of diffusion as a phenomenological description of the molecular motion, and on the coupled mode theory, is developped to describe single-beam surface relief grating formation in azopolymers thin films. It allows to explain the mechanism of spontaneous patterning, and self-organization. It allows also to compute the surface relief profile and its evolution in time with good agreement with experiments.