Through-thickness temperature gradients in double-layered magneto-optical media for direct overwrite

The effect of through-thickness temperature gradients in thin films irradiated by short laser pulses is described, together with its application to direct overwrite. We found by simulation that through-thickness temperature gradients become substantial when a medium is irradiated by short laser pulses of the order of 1 ns which is the characteristic time of heat diffusivity. This effect qualitatively explains why in writing experiments on a double-layered medium short pulses expand the laser power range for a writing process.