An optical magnetometer based on the magneto-optical Kerr effect

摘要

Contemporary, the magneto-optical Kerr effect present in the base of methods used to analyze magnetization of surfaces and thin layers is a point of a great interest. A local application, high sensibility and fast feedback belong to its advantages. The paper shows some results obtained while verifying the functionality of a new one-beam magnetometer setup designed in ILC at Bratislava. A great numerical aperture of the objective used to direct both, the light incident and light reflected from the sample, provided a high mechanical stability of the setup, important especially when low-intensity light recorded. The recording electronics enabled to average the measured signal and suppress the broadband noise. A 70 nm thick layer of Co deposited on Si substrate in AC external magnetic field and longitudinal, polar and transverse configurations was used. Obtained results showed the influence of he light polarization (TE, TM) and wavelength (450 nm, 640 nm) on the magneto-optical Kerr effect detection sensitivity. The mutual influence of the components of the resulting magnetization of the sample was observed and discussed, too.