Spot and mark-size characterization in magneto-optic recording

The attainable performance of a magnetooptic (MO) recording system is determined by the laser intensity profile and the size and shape of the written magnetic domain. The authors present a computer model that provides MO readout waveforms based on an overlap integral of the scanning laser spot and the written domains. This model and regression analysis are applied to experimental magnetooptic readout waveforms, and the laser profile and mark size are determined. A nonlinear least-squares fit of readout data yields a unique determination of the laser-spot profile and written-domain size. The effects of groove width and thermal blooming on domain shape can be included in the modeling. The results are compared to those of other spot and domain measurements, and close agreement is obtained