Writing temperature estimation in thermomagnetic recording

A thermal conduction model calibrated with the aid of the measured temperature dependence of the magnetooptic (MO) Kerr effect and MO recording readback data taken with variable reading laser power and disk velocity has been used to provide an estimate of the absolute writing temperature in thermomagnetic recording on MO media. This procedure assumes that such writing is essentially a thermal thresholding phenomenon and that magnetic effects in writing are secondary. The key elements of this method include the following: (a) availability of a flexible thermal model properly calibrated for the MO media under study; (b) measurements of the Kerr rotation of the MO material versus temperature; (c) an accurate experimental method for measuring the differential Kerr readout signal with a dynamic MO disk tester; and (d) experimental data of thermomagnetic writing that is well fitted by a model illustrating the validity of the simple threshold writing temperature concept. The simultaneous regression fitting of a thermal model of MO readback to experimental data results in a fully self-consistent procedure.<
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