CAREER: Computational Studies of New Metallodielectric Structures for Manipulating Light At Sub-wavelengthscales

Stanford University, Stanford CA

Investigators

Abstract

Recent experimental and theoretical efforts on periodic metallic structures have led to the discoveries of a number of extraordinary optical and electromagnetic phenomena. Many of these phenomena are pointing towards new possibilities of confining, transmitting and manipulating light at a length scale that is far smaller than the wavelength of incident photons. Two recent examples include the experimental discoveries of plasmon-assisted high transmission through sub-wavelength apertures, and the theoretical proposal for constructing a lens with a negative refractive index that allows for focusing at infinite resolution. These discoveries are leading to new device possibilities in nano-fabrication and imaging. These developments, in turn, raised many interesting theoretical questions. A key ingredient in all these phenomena is the use of micro and nano-structured metallic objects. Therefore, we need to understand in general how micro and nano-structures interact with sub-wavelength features in the electromagnetic fields. Since the novel effects here directly result from the subtle interplay between the structural and geometrical parameters. It is important to undertake theoretical studies that take into account the full complexity of the structures in a first-principles way. We propose to undertake a series of large-scale simulations to elucidate the basic mechanisms associated with these phenomena, and to explore new structures that might exhibit further interesting properties. In particular, we will study the effects of microstructure on the resolution of focusing, and the detailed mechanisms of using aperiodic structures to assist tunneling through a single aperture. We will also explore the use of hybrid metal and dielectric periodic structures as a novel negative refractive index material that might be scaled down into the optical domain. These studies will enhance our understanding in this new regime of optics, and will lead to new opportunities for device applications. This program, in combination with my other research programs on photonic crystals and micro-photonic devices, will provide excellent research and educational opportunities for students. The students will gain a deep theoretical understanding by pursuing research in a new regime of optics. At the same time they will have ample opportunities to collaborate with experimental groups in optics and in nano-fabrication. The students will also learn state-of-the-art computational techniques. In addition, the research program is designed so that undergraduate and M. S. students can take on short-term projects to carry out sets of well-defined simulation studies. Finally, in order to share our excitement in this research field with the general public, we will explore the possibility of constructing a sculpture of an acoustic crystal, so that a visitor may directly experience the remarkable band gap effect.