On the efficient mixed amplitude and phase grating recording in vacuum deposited Disperse Red 1

Abstract

We report on two-dimensional optical storage photochromic material made of Disperse Red 1 (DR1) thin film vacuum deposited on glass substrate. Holographic mixed amplitude and phase gratings were recorded in highly organized DR1 thin molecular films with 488 and 514.5 nm cw Ar + laser light using degenerate two-wave mixing technique. Self-diffraction efficiency measured within Raman–Nath scattering limit reached 3.5%. The light scattering was mostly due to presence of periodic absorption changes (amplitude grating) as it was established from grating translation technique. Kinetics of grating recording was studied as a function of incident light intensity allowing to formulate the possible mechanism of grating build-up process in the studied film. Polarizing microscopic studies revealed the presence of light induced optical anisotropy possibly connected with heat-induced crystallization. Absorption grating profiles were analyzed in relation to exposure conditions.