Numerical simulation of recorded domain shapes on a rotating magneto-optical disk

For realizing a very high density magneto-optical recording such as a domain-edge recording, the way to control domain shapes and sizes precisely was studied by comparing a numerical simulation with an optical observation of recorded domains on a high-speed rotating disk. The numerical simulation based on a heat flow analysis was applied to a multilayer structure disk. A teardroplike domain shape was analyzed by this simulation, which causes a timing error of edge detection. This shape could be corrected to a symmetrical shape by using a modulated laser pulse. Moreover, it was found that a distance between two domains was affected by a thermal correlation of two laser pulses. This effect is remarkable when the time interval between two pulses is short.