A combined transverse/polar Kerr-effect system for magnetic measurements on Co-Cr perpendicular orientation on computer discs

This paper describes a Kerr magneto-optic effect apparatus for measuring in-plane and perpendicular magnetic properties of Co-Cr coated computer discs. A combined differential amplifier, phase-sensitive detector technique was used to achieve a signal-to-noise ratio of 46 dB in the perpendicular system. Comparisons are made with v.s.m. measurements and results presented for 5.25" Winchester discs.