Thin azo-polymer films for reversible holographic recording

Polymethylmetacrylate with covalently bound side-chain azo- benzene group is synthesized and thin films are fabricated. Holographic grating recording is achieved with a 442 nm He- Cd laser at three different grating spacing: 646, 1340 and 2220 nm. The dependence of the diffraction efficiency on time is investigated. The optical recording is stable for more than four years at room temperature. Optical erasure can be performed with circularly and linearly polarized laser light.