Holographic grating inscription in DR1: DNA-CTMA thin films: the puzzle of time scales

Abstract

We study experimentally the dynamics of holographic inscription of gratings in DR1:DNA-CTMA thin films using a degenerate two-wave mixing (DTWM) setup in its initial phase (30 ms) and in a longer time interval (30 s). The temporal pattern of evolution of diffraction efficiency is complex, simple fitting procedures fail to reproduce the data. We point out that the complex dynamics can originate a large span of temporal scales, closely related to the microscale inhomogeneity of local free volume. Some of its hallmarks are found through Monte Carlo simulations.