A Comparison of Enthalpy and Temperature Methods for Melting Problems on Composite Domains

Abstract

In optical rewritable recording media, such as the Blu-ray Disc, amorphous marks are formed on a crystalline background of a phase-change layer, by means of short, high power laser pulses. It is of great importance to understand the mark formation process, in order to improve this data storage concept. The recording layer is part of a grooved multi-layered geometry, consisting of a variety of materials of which the material properties are assumed to be constant per layer, but may differ by various orders of magnitude in different layers. The melting stage of the mark formation process requires the inclusion of latent heat. In this study a comparison is made of numerical techniques for resolving the associated Stefan problem. The considered methods have been adapted to be applicable to multi-layers.