FDTD analysis of recording light distribution in near-field MAMMOS recording system

In this study we utilise the finite difference time domain (FDTD) method to numerically solve the time-domain Maxwell curl equations in the derivative form to produce simulations of the cross-sectional focused light intensity distribution through the multilayered MAMMOS thin-film structure. However, via Bouguer theory, the approach described in this paper provides a rigorous model to obtain the true appearance of the heat source distribution. The model also permits variation of several system parameters such as the NA and the individual layer thicknesses to facilitate optimisation of the distribution. This paper examines the dependence, of the light intensity distribution through the recording layer on the disk structure and air gap, both of which are analyzed in detail, as are the relevant beam spot profiles. Additionally, investigation into both the polarization of the cross-sectional light distribution and the effect of the variation of the incident beam polarization on the recording light distribution is carried out.