Recrystallization dynamics of phase change optical disks with a nitrogen interface layer

The recrystallization velocity of a phase change material is measured in real lime by observing the reflected laser power during the interaction of the laser with the sample. This technique is applied to compare the recrystallization behavior of phase change optical disk media with and without a nitride interface layer. It is shown that the enhanced cyclability induced by the nitride interface layer is correlated to an enhancement of the recrystallization velocity. The experimental determination of temperature profiles induced by laser pulses, combined with the numerical integration of the crystallization rate equations, leads to a quantitative interpretation of the observed recrystallization dynamics.