Measurement of Magneto-Optical Kerr Effect Using Piezo-Birefringent Modulator

An advanced magneto-optical technique is described, which allows simultaneous determination of two mutually-conjugate parameters–Kerr rotation and reflectance magneto-circular dichroism–using a piezo-birefringent modulator. This technique provides a sensitivity of 0.002° for Kerr rotation at λ=500 nm with 12 nm resolution, using a halogen lamp (150 W) as the light source. The wavelength region covered by the method can be extended from 300–2500 nm by suitable selection of gratings and light detectors. The new technique was used to measure magneto-optical hysteresis loops for several wavelengths and magneto-optical spectra on an rf-sputtered amorphous Gd-Co film, and the results are reported here.