Magneto-Optical Kerr Effect And Its Detection

The magneto-optic Kerr effect (MOKE) is the phenomenon that the light reflected from a magnetized material has a slightly rotated plane of polarization. We can make use of the MOKE to obtain magnetic information by detecting the polarization of the reflected light. In macroscopic formalism, the MOKE is derived from the changed dielectric tensor because of magnetization. It is similar to the Faraday Effect where the plane of polarization of the transmitted light is rotated. With the laser technology developing and a lot of new functional magnetic materials coming out, the MOKE is being applied to many fields, such as magneto-optical storage and surface magnetism research. Now, the SMOKE is significant to the social production and scientific research. One of the most difficult to the detection of the Kerr rotation is the noise caused by the power fluctuation of the light source. We used two main means to get over these noises. One of the methods is about the modulation of the detected beam, the other one is the balanced polarimetry technique.In this thesis, magneto-optic Kerr effect of macroscopic classical theory was analyzed. According to Macroeconomic Theory, we analyzed the relationship between Magneto-optic Kerr effect and Faraday Effect. Then we developed a magneto-optical Kerr effect detection device, taking advantage of the modulation of the detected beam and balanced polarimetry technique. The sensitivity of the device reaches the 5 x 10-4 degree. The first part is the theoretical analysis of the magneto-optical Kerr effect. The second part describes in detail the various parts of the experimental device. And the third part shows the detection process and the detect data.