Phase Change Recording Media of 20GB Capacity (AOD) For System with 0.6mm-thick Substrate : Media Technology for Obtaining Larger Data Density

Abstract

We have developed phase change media of 20GB user data capacity for the next generation optical recording system using a blue-violet laser diode with the wavelength of 405 nm. An objective lens with the numerical aperture of 0.65 has been used along with 0.6 mm-thick substrates on which the laser is incident. We have employed the land and groove recording. A transparent film with high thermal conductivity has been adopted at the light incident side of the recording layer in order to improve the carrier to noise ratio and the erase ratio as well as to reduce the cross-erase. Bottom channel bit error rate of less than 1x10 6 has been obtained and its wide tilt margins have successfully demonstrated the strong feasibility for the next generation rewritable system.transparent thermal control layer