Directional Beaming by Interaction of Dielectric Nano Surface Structure and Metal : Design for Fabrication of Nanowriter Optical Head

Abstract

Based on the Extraordinary transmission and directional beaming phenomena proposed by Ebbesen et al, novel optical head structures are presented. Non-metal optical head composed of dielectric surface grating on a metallic thin film was proposed. In this thesis, simulation tools and experiments were carried out to prove that non-metal optical head works as metal optical head previously reported. Analyzing the simulation results, surface plasma is shown to play an important role in the directional beaming phenomenon. The main reason for designing non-metal optical head proposed in this thesis is for mass production possibilities. Knowing the mechanism which drives the directional beaming phenomenon for non-metal optical head, design rule for desired non-metal optical head is presented. Another novel optical design proposed is double slits optical head. Light emerging from the two slits cross at the desired focal length, which is decided by the distance between the two slits. Also, the two beams interference to become a subwavelength light spot. Therefore, by designing the surface structure of double slits optical head, it is possible to achieve subwavelength focal spot with unprecedented focal length that appears to bypass the Rayleigh criteria.