A Thermal Analysis of a Magneto-Optical Recording Mechanism with the Magnetic Field Modulation Method on a Land and Groove Substrate

Abstract

The power tolerance in recording is one of the most significant issues in the case of rewritable optical disk systems. Magneto-optical land/groove recording has been investigated by magnetic field modulation with pulse irradiation. The lower limit and the upper limit of the power tolerance are determined from the overwriting and the crosswrite characteristics, respectively. The experimental dependence of the power tolerance on track pitch, pulse duty, and optical spot size has been in good agreement with our model based on the thermal analysis. According to our model, the mark width is exactly the width of a recording track for the lower limit of power tolerance, and it spreads into the neighboring track for the upper limit. The deep groove substrate has been found experimentally and theoretically to be effective for improving the power tolerance.