Vector diffraction from subwavelength optical disk structures: Two-dimensional near-field profiles

An efficient finite-difference frequency-domain method is developed for calculating electromagnetic fields in the neighborhood of subwavelength dielectric and metallic structures. The method is used to investigate two-dimensional near-field and far-field patterns of a focused beam diffracted from an optical disk, specifically from a DVD (Digital Versatile Disk). It is shown that the polarization of illumination has a significant impact on diffraction patterns as expected and that scalar theory does not provide an accurate-analysis of diffraction from a DVD.