Nanoplasmonic waveguides: towards applications in integrated nanophotonic circuits

Abstract

The properties of propagating surface plasmon polaritons (SPPs) along one-dimensional metal structures have been investigated for more than 10 years and are now well understood. Because of the high confinement of electromagnetic energy, propagating SPPs have been considered to represent one of the best potential ways to construct next-generation circuits that use light to overcome the speed limit of electronics. Many basic plasmonic components have already been developed. In this review, researches on plasmonic waveguides are reviewed from the perspective of plasmonic circuits. Several circuit components are constructed to demonstrate the basic function of an optical digital circuit. In the end of this review, a prototype for an SPP-based nanochip is proposed, and the problems associated with building such plasmonic circuits are discussed. A plasmonic chip that can be practically applied is expected to become available in the near future. The prospects for creating sophisticated nanophotonic circuits by harnessing the opportunities provided by plasmonics are exciting. Yurui Fang and Mengtao Sun from the Beijing National Laboratory for Condensed Matter Physics review recent progress in the development of various components and devices for generating, manipulating and detecting surface plasmon polaritons — tightly confined waves that can be excited by light at the interface between a metal and a dielectric. Their small size offers opportunities for constructing photonic devices that are smaller than the wavelength of light, a major barrier to the miniaturization of optical integrated circuits. Fang and Sun describe how nanoscale waveguides, multiplexers, lasers, high-speed modulators, logic gates and detectors for surface plasmon polaritons are all coming to fruition. They also consider the future prospects of this technology.