Theoretical study on all-optical magnetic recording using a solid immersion lens

Abstract

We present a simple model for performing high-density all-optical magnetic recording using a solid immersion lens. The magnetization distribution in the magneto-optic film placed in the vicinity of the solid immersion lens is studied using the vector diffraction theory and the inverse Faraday effect. Simulation results show that although the transverse components of magnetization are nonzero, the axial component dominates. The magnetization direction of the axial component can be reversed by changing the helicity of the incident circularly polarized laser pulses. For a lower-numerical-aperture (NA) system, a larger and circular magnetization zone is obtained and the deviation angle of magnetization direction departing from the optical axis is smaller in the effective magnetization zone, which is useful to vertical magnetic recording. For a higher-NA system, a smaller magnetization zone is generated, but the three-dimensional magnetization distribution has to be considered.