POTENTIALITY OF THE AG-IN-SB-TE PHASE-CHANGE RECORDING MATERIAL FOR HIGH-DENSITY ERASABLE OPTICAL DISCS

The feasibility of using Ag-In-Sb-Te phase change material for high de nsity of directly overwritable optical discs has been studied. A linea r density of 0.34 mu m/bit with a track pitch of 0.74 mu m is confirme d to be achievable with a light source wavelength of 680 nm, with an o bjective lens NA of 0.60 and the criteria of data-to-data jitter of le ss than 14% of the channel bit length. The recording characteristics a re also studied using an optical system with a 635 nm red laser diode in order to investigate the attainment of a linear density of 0.267 mu m/bit which is equivalent to the DVD-ROM (read only memory) specifica tion.