Figure of merit in MO readout with polar and transverse Kerr effects

Readout in magnetooptical (MO) disk is discussed. MO signals obtained with transverse, longitudinal and polar Kerr effects are proposed from the viewpoint of the figure of merit of readout. The comparison was done in materials with or without perpendicular magnetization, and included the dependencies on the incident angle of the beam. Although the incident angle must be large, PtMnSb gives larger figure of merit in transverse Kerr readout than TbFeCo in polar Kerr readout at a wavelength of 415 nm