Performances of pregrooved phase-change rewritable media in the 680-nm laser diode system

The performances of the pregrooved Phase Change Rewritable (PCR) media have been measured by using an test drive which optical head have a 680 nm laser diode and focus lens with numerical aperture of 0.55. The write/read characteristics and groove parameters have been measured. The linear density of 1.42 Kbits/mm by using Pulse Position (PPM) recording method and track pitch of less than 1 micrometers are expected to be realized.