Super-resolution effect of semiconductor-doped glass

Semiconductor-doped glass is proposed as a super-resolution layer for future ultra-high-density optical disc systems. It was confirmed that this material system showed very fast response and large transmittance change by laser-beam irradiation when CdSSe-doped glass was used. The rise time of the transmittance change was less than 10 ns and the transmittance change reached 30%. These optical responses were obtained at a power density of the pumped laser beam of 1 MW/cm(2). This power density corresponds to the readout power in digital versatile disk-read only memory (DVD-ROM) and digital versatile disk-random access memory (DVD-RAM) discs. This material system is regarded as a potential candidate for a super-resolution readout layer that is applicable to both ROM and RAM discs.