Hologram recording in azobenzene oligomers

摘要

Elementary hologram (holographic grating) recording and their coherent optical erasure have been experimentally studied in azobenzene oligomer (ABO) layers differing by their chemical composition, matrices and by the connection type of azobenzene chromophores to the matrix (dispersed or covalently bound). The best holographic parameters (7.9% diffraction efficiency and 86 J/cm~2 specific recording energy) were achieved in the samples with covalent bonding to the matrix. Vector recording is also possible. Recording is unstable and reversible. The coherent optical erasure studies have shown its efficiency dependencies on the initial diffraction efficiency, erasing beam intensity and grating period which are different for three groups of ABO samples. The conclusion is made that recording is due to the photoinduced alignment of the azobenzene chromophores followed by refractive index changes. These are the first results and further studies are in progress.