PEPTIDE OLIGOMERS FOR HOLOGRAPHIC DATA-STORAGE

SEVERAL classes of organic materials (such as photoanisotropic liquid- crystalline polymers(1-4) and photorefractive polymers(5-7)) are being investigated for the development of media for optical data storage. H ere we describe a new family of organic materials-peptide oligomers co ntaining azobenzene chromophores-which appear particularly promising f or erasable holographic data storage applications. The rationale for o ur approach is to use the structural properties of peptide-like molecu les to impose orientational order on the chromophores, and thereby opt imize the optical properties of the resulting materials. Here we show that holographic gratings with large first-order diffraction efficienc ies (up to 80%) can be written and erased optically in oligomer films only a few micrometres thick. The holograms also exhibit good thermal stability, and are not erased after heating to 180 degrees C for one m onth. Straightforward extension of this peptide-based strategy to othe r molecular structures should allow the rational design of a wide rang e of organic materials with potentially useful optical properties.