Abstract

Phase-change media [1] in DVD-RAM systems has been a hot bed of research in the past several years. In phase-change optical recording a high power "write" beam irradiates the disk and forms an amorphous mark. The amorphous mark is written in a crystalline background. The difference in the optical constants between the amorphous and crystalline areas enables the amorphous mark to be read back by a "read" beam of substantially lower power compared to the "write" beam. An "erase" beam with a power level less than the write beam can be used to erase the amorphous mark. The erase beam raises the temperature of the phase-change layer to a value that is conducive for rapid crystallization.

© 1998 Optical Society of America