Optical Nanotransmission Lines: Synthesis of Planar Left-Handed Metamaterials in the Infrared and Visible Regimes

Following our recent theoretical development of the concept of nano-inductors, nano-capacitors and nanoresistors at optical frequencies and the possibility of synthesizing more complex nanoscale circuits, here we theoretically investigate in detail the problem of optical nano-transmission lines (NTL) that can be envisioned by properly joining together arrays of these basic nano-scale circuit elements. We show how, in the limit in which these basic circuit elements are closely packed together, the NTLs can be regarded as stacks of plasmonic and non-plasmonic planar slabs, which may be designed to effectively exhibit the properties of planar metamaterials with forward (right-handed) or backward (left-handed) operation. With the proper design, negative refraction and left-handed propagation are shown to be possible in these planar plasmonic guided-wave structures, providing possibilities for sub-wavelength focusing and imaging in planar optics, and laterally-confined waveguiding at IR and visible frequencies. The effective material parameters for such NTLs are derived, and the connection and analogy between these optical NTLs and the double-negative and double-positive metamaterials are also explored. Physical insights and justification for the results are also presented. Comments Copyright 2006 Optical Society of America, Inc. Postprint version. Published in Journal of the Optical Society of America B, special issue on "Metamaterials," Volume 23, Issue 3, March 2006, pages 571-583. This journal article is available at ScholarlyCommons: http://repository.upenn.edu/ese_papers/259 Accepted for publication in JOSA B Focus Issue on Metamaterials, to appear in March 2006 Issue -1Optical Nanotransmission Lines: Synthesis of Planar Left-Handed Metamaterials in the Infrared and Visible Regimes Andrea Alù University of Pennsylvania, Dept. of Electrical and Systems Engineering, Philadelphia, PA 19104, U.S.A. University of Roma Tre, Dept. of Applied Electronics, Rome, Italy Nader Engheta University of Pennsylvania, Dept. of Electrical and Systems Engineering, Philadelphia, PA 19104, U.S.A.