Directional beaming by interaction of dielectric nano surface structure and metal: design for fabrication of nanowriter optical head

Abstract

The extraordinary transmission phenomenon has stimulated much interest in recent years. Based on the extraordinary transmission and directional beaming phenomena proposed by Ebbesen et al., a new optical head structures, nonmetal optical head, are presented in this letter. Nonmetal optical head composed of dielectric surface grating on a metallic thin film was proposed. We also offer the physical origin for the directional beaming of light emerging from a single subwavelength slit in the metallic film that has dielectric grating feature on the exit side. Both of experiments and numerical simulations were implemented, and they were shown eventually to agree with this surface plasmon diffraction very well. The main reason for designing nonmetal optical head proposed in this letter is for mass production possibilities of nanoimprint technique. It is very important to know the mechanism which drives the directional beaming phenomenon for nonmetal optical head. Therefore, a design rule for desired nonmetal 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, two light beam interference to become a subwavelength light beam. Various applications may appear because of the understanding of this nano-optics device, from this design, for example, an optical switch or an optical sensor, optical lithography, optical storage, and optical microscopy, and so on.