Abstract
In magneto-optical technology, the interest for magnetic coupled layers has increased in the last decade with the development of new methods like the Magnetic Super Resolution (MSR) and the Magnetic Amplification of Magneto-Optical System (MAMMOS), allowing improvement in recording density. In this framework, hysteresis loops of a GdFeCo/TbFeCo bilayered structure are studied. For the rare-earth transition metal (RE-TM) alloys in the infrared and visible light wavelength, the Kerr and Faraday rotations are predominantly due to the transition metal magnetization. Experimental results show that the relation between the sign of the rotation and the transition metal (TM) magnetization direction is not so obvious but depends on several parameters like the material thicknesses and the optical and magneto-optical constants. The experimental investigation of the structure is complemented by optical simulations where great variations on the rotation order of magnitude and rotation sign are also obtained. The analytical model of the system shows that these variations are due to the interferences occurring in the layered structure.
