Analysis of Scattering Light from Magnetic Material with Land/Groove by Three-Dimensional Boundary Element Method

Abstract

A calculation method with three-dimensional Boundary Element Method (BEM) has been developed for analyzing scattering light from a magnetic material, in order to determine the contribution of land/groove shapes and incident beam polarization to Kerr rotation. A product of scattering beam intensity and the Kerr rotation angle (R·θk) has been calculated in the case that 680 nm wavelength Gaussian beam is focused on 680 nm or 1360 nm width land/groove, which has 85 nm depth or height. The land or groove shapes have been varied from rectangular shapes to V-shapes. Regardless of the land/groove shapes, the R·θk of lands is larger than that of grooves in TM-polarization and smaller in TE-polarization. The results in verification experiments well met the calculated ones, i.e., the carrier level of lands is higher than that of grooves in almost the entire range of recording frequency for TM-polarization light, and it is lower for TE-polarization.