The photoinduced birefringence and mass transport in azo compound K-D-2

Abstract

Azobenzene containing compounds are among light polarization sensitive materials – the moieties may align relative to the electric field vector of light, leading to anisotropy and birefringence in the sample. Another phenomenon which can be observed in azo compounds under influence of light is macroscopic movement of the material. In this work photoinduced processes in low molecular weight organic glass – bis-azobenzene containing compound K-D-2 were experimentally studied. Birefringence was induced with linearly polarized laser light (473, 532 and 635 nm) and measured at 633 nm wavelength. Polarization holography with recording beam configuration +45°/-45° was used to induce mass motion. Dependence of the surface relief depth on the recording laser wavelength in the visible spectrum (375 – 671 nm) was obtained. Formation of the SRG was observed with all used wavelengths and high birefringence values were obtained. Certain correlation between the absorption of the wavelength and photoinduced mass transport and birefringence is yet to be confirmed.