Modeling of Laser Pulsed Heating and Quenching in Optical Data Storage Media

Rewritable optical data storage using phase change materials holds considerable promise for upcoming multi-media and mass storage applications. To compete with advances in other storage technologies, it is of crucial importance to increase the data transfer rate and storage capacity. Near-field recording should enable considerable progress in these areas. Currently available near-field light sources, however, are limited by their low output powers. This puts seven constraints on the thermal properties of the phase change media. This paper addresses how rewritable optical data storage media can meet these requirements. In particular, the required laser power for writing and erasing sub-micron "bits" is calculated. It is shown how the power and the write and erase times depend on the structure and thermal properties of the media, as well as on the crystallization kinetics of the recording layer. Guidelines to media optimization and areas that presently pose the most serious limitations are presented.