Non-volatile holographic data storage media based on dye-doped thermoplastic

Holographic data storage materials are currently being developed at General Electric. These materials are based on a thermoplastic host doped with narrow-band absorption dyes. The dyes are photosensitive and undergo non-reversible photochromic reactions upon exposure. Samples were produced using different dyes and various concentrations in a polycarbonate host with a focus on sensitivity and capacity of the media. A challenging obstacle for a successful photochromic system is the inherent remaining photosensitivity of the material after the writing process. This paper will introduce the concept of a highly sensitive yet non-volatile photochromic data storage system. The chromophore is subjected to a post-treatment step at a second wavelength which removes the photosensitivity. The stored data can therefore be secured against degradation during read-out at the writing wavelength.