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. Keywords: nanophotonics; plasmonic chip; plasmonic circuit; surface plasmons; waveguide INTRODUCTIONThe technologies of semiconductor integrated circuits and modern electronic integrated devices are rapidly approaching their fundamental limits in terms of both speed and data transmission rate (DTR).1 One of the promising solutions to these problems is using light rather than electrons in the functional processing components.2 However, the feasibility of fabricating nanoscale photonic devices may be limited because the diffraction limit of light is dominant when the size of a photonic device is close to or smaller than the wavelength of light in the material. Surface plasmon polaritons (SPPs), electromagnetic waves coupled to charge oscillation at the metal dielectric interface, can circumvent the diffraction limit and achieve localisation of electromagnetic energy in nanoscale regions that are considerably smaller than the wavelengths of light in the material. 3 The electromagnetic field perpendicular to the interface between metal and dielectric decays exponentially with distance from the metal surface while maintaining the long-range propagation of electromagnetic energy along the surface. This essential feature of SPPs can enable the fabrication of photonic components and optical signal processing devices at the sub-wavelength scale.Surface plasmons (SPs) include the localised type (localised surface plasmons, LSPs) and propagating type (propagating surface plasmon polaritons, PSPPs). For the purpose of optical signal transportation and nanophotonic circuits, only PSPPs will be considered in this review, and they are referred to as SPPs hereafter. Because of the unique properties of tightly confined SPPs on metal structures, various types of metallic nanostructures, such as nanoparticle chains, 4-7 thin metal films, 8 metal slits, 9 grooves, 10 chemically synthesised metal nanowires (NWs)

Exciton-plasmon coupling interactions: from principle to applications

“…The mechanism involves the excitation of the SP and chemical enhancement is associated with charge transfer, also known as charge transfer resonance Raman [29,164,165]. When the incident light illuminates the metal surface, metal nanostructures have the ability to compress light into a small volume between two nanoparticles, and the EM field strength of the region is greatly enhanced to produce a hotspot (see Figure 9) [167,168]. Under the mechanism of EM enhancement, the factor of SERS enhancement factor can be expressed as [169] σ ω σ ω =…”

All dielectric metamaterial loaded tunable plasmonic waveguide

“…13 The propagation length has been observed to be comparable with the values found in literature for wave guiding application at telecommunication wavelength. 5,10 The waveguide characteristics with the variation of height (number of unit cells) at fixed width have also been analyzed. Fig.…”

“…[1][2][3][4][5] The never-ending search of deeply sub-wavelength photonic devices for greater compactness, higher speed and reduced optical power has caused the emergence of optical components based on Surface Plasmon Polaritons (SPPs). Surface plasmon polaritons are surface waves originated from the collective oscillations of free electrons and photons which propagate along the interface of two media where real part of permittivity possesses opposite signs.…”

“…Surface plasmon polaritons are surface waves originated from the collective oscillations of free electrons and photons which propagate along the interface of two media where real part of permittivity possesses opposite signs. [5][6][7][8][9][10] A variety of configurations such as Metal-Insulator-Metal (MIM), 11 Insulator-MetalInsulator (IMI), 12 Dielectric loaded SPP (DLSPP), 4,[13][14][15][16] Channel Plasmon Polariton (CPP), 17,18 Wedge SPP, 19,20 Hybrid Plasmon polariton (HPP), 21,22 plasmonic waveguide cladded by hyperbolic metamaterial [23][24][25] etc. have already been proposed.…”

Thermal dynamics of silver clusters grown on rippled silica surfaces

“…LSPR based research has seen a boom at the present time which is primarily due to the ease of fabrication of metallic nanoparticles in a variety of environments 7,8 . Especially, the case of ordered chains of silver nanoparticles on patterned templates 9,10 is interesting for their use in nanoplasmonic waveguides 11,12 .…”