Optical and recording properties of short wavelength optical storage materials

Research interests in short wavelength optical storage have been growing co nsiderably in recent years. In this paper, we first present a brief introdu ction to the materials requirements for short wavelength optical storage an d basic considerations on the relation between reflectivity and optical con stants of the materials, and then report our experimental results on the op tical and short wavelength recording properties of the azo dye and the phas e change compounds, Ge2Sb2Te5 and Ag8In14Sb55Te23, The reflectivity contras t due to optical recording at 514.5 nm in the dye-polymer film is as high a s 25%. The change in n and k of the phase change materials due to heat trea tment can cause reasonably high reflectivity change at 500 nm, writing and erasing at 514.5 nm result in moderate reflectivity contrast. These suggest that the materials can be used for short wavelength optical storage. (C) 2 000 Elsevier Science S.A. All rights reserved.