STUDIES ON THE RELATION BETWEEN THE EIGENVALUE AND ENHANCEMENT OF KERR-EFFECT FOR MAGNETOOPTICAL MATERIALS

Based on the universal additivity law of the interference of light the following was achieved. (i) An analytic representation between the' eigenvalue of the Kerr rotation angle theta(k)0 and the enhanced theta(k) for a double-layered film, theta(k) = en1 theta(k)0, was obtained theoretically, where e is the enhancement factor and n1 is the refractive index of the dielectric medium. (ii) An analytic representation between theta(k) and theta(k)0 (theta(k) = e013e123n2theta(k)0) of the trilayered film [bilayered transparent media and monolayered magneto-optical (MO) medium], was also obtained, where e013 and e123 are the enhancement factors: The calculated theta(k) value is in good agreement with experimental results for e = 1. In general, the theoretical calculation shows that theta(k) is related to the thickness of the transparent media. Thus, if one wants to get an optimum value for theta(k), the thickness of the first transparent film layer (such as a glass substrate) must be selected carefully. It also shows that if the variation of the thickness of the glass substrate is 5 nm, theta(k) could vary by 0.1-degrees for MnBiCe films. (iii) The relation connecting theta(k) with theta(k1)0 and theta(k2)0 for bilayered MO films has been theoretically studied, where theta(k1)0 and theta(k2)0 are the eigenvalues of the Kerr rotation angle of MO materials 1 and 2, respectively. Finally, theta(k) for a Fe/Co film was calculated.