Advances in thermal modelling of dual-layer DVR-blue fast-growth media

摘要

Dual-layer phase-change recording is an option to further increase the data-capacity of re-writable optical discs. A numerical model based on crystal growth was used to study formation and erasure of amorphous marks in dual-layer stacks based on fast-growth doped eutectic SbTe phase-change materials. The effect of the linear velocity, erase power, and crystal growth velocity on the erasability of amorphous marks was simulated. The calculated effects are in good agreement with the phenomena observed from DVD and DVR measurements. Mark formation in slow-cooling dual-layer stacks is characterised by severe re-crystallisation during writing. Two possible solutions are indicated in the paper aimed at reducing the heat accumulation in the recording stack, and thus re-crystallisation, during writing of amorphous marks. Additional transparent heat sinks improve the mark formation considerably but also require higher write powers. Another solution is based on an appropriate write strategy. Recording results obtained with such a write strategy are shown.