Quantum Dot-Based Local Field Imaging Reveals Plasmon-Based Interferometric Logic in Silver Nanowire Networks

Abstract

We show that the local electric field distribution of propagating plasmons along silver nanowires can be imaged by coating the nanowires with a layer of quantum dots, held off the surface of the nanowire by a nanoscale dielectric spacer layer. In simple networks of silver nanowires with two optical inputs, control of the optical polarization and phase of the input fields directs the guided waves to a specific nanowire output. The QD-luminescent images of these structures reveal that a complete family of phase-dependent, interferometric logic functions can be performed on these simple networks. These results show the potential for plasmonic waveguides to support compact interferometric logic operations.

Nanowire-supported plasmonic waveguide for remote excitation of surface-enhanced Raman scattering

“…However, the larger difference between CIDs at terminals of another nanowire (c or d) and the illuminating terminal showed that the CID could be manipulated by the chirality of a nanostructure, such as through the coupling angle between two Ag nanowires, the morphology of the Ag terminals, and the distance of the coupling. [6][7][8][9] In this system, the CID increased while the crossing angle was less than 90 6 (terminal c) and Nanowire supported plasmonic waveguide for RE-SERS YZ Huang et al 14 decreased, while the crossing angle was larger than 90 6 . These experimental results demonstrated that the ROA could be remotely excited and enhanced by chiral PSPPs, which had the potential to remotely determine the molecular chirality or the absolute configuration or conformation of a chiral living cell.…”

“…[102][103][104][105][106][107][108] We have demonstrated that this enhancement could also be realized through remote SERS of fmoc-glycyl-glycine-OH in an Ag nanowire system in rapid communications (Figure 20). 70 The SEM image and the optical image of the PSPPs present in Figure 20a and 20b indicated that the crossing angle between the nanowires was determined to be approximately 20 6 and released light at the terminals of the nanowire. The local and remote Raman images of fmoc-glycyl-glycine-OH at 1593 cm 21 , excited by left-and right-circularly polarized light, are shown in Figure 20c and 20d, respectively.…”

“…9 Interestingly, for the nanowires that could only support the three lowest SPP modes ( m j jƒ1), as shown in Figure 5, the plasmonic waveguide would exhibit a helix behavior. 6,9 Due to a constant phase delay of p/2 between the m51 and m521 SPP modes, a circularly polarized prop- Nanowire supported plasmonic waveguide for RE-SERS YZ Huang et al 4 agating SPP could be generated by the coherent interference when the two SPP modes have equal amplitude. This circularly propagating SPP is stretched by the simultaneously excited m50 SPP mode into a helical SPP wave at the nanowire surface.…”

“…The former could overcome the traditional diffraction limit in dielectric optics and be the key approach to overcoming the bottleneck of the miniaturization of nanophotonic devices and large-scale on-chip integrated circuits for next-generation information technology. [5][6][7][8][9][10][11] The extremely enhanced EM field caused by the latter has great application values in various fields, such as surface-enhanced spectrum, [12][13][14][15] surface plasmon resonance sensors, [16][17][18][19] ultra transmission, 20,21 plasmonic trapping, 22,23 plasmonic-enhanced emission, 24,25 quantum communication, 26,27 super-resolution microscopy, 28 cloaking, 29 photothermal cancer therapy, 30,31 steam generation, 30,32,33 holography, 34 photovoltaics [35][36][37] and water splitting. [38][39][40] One of the most promising applications of SPPs, especially localized SPPs, is surface-enhanced Raman scattering (SERS), which has been studied both theoretically and experimentally for many decades.…”

Dye-Assisted Gain of Strongly Confined Surface Plasmon Polaritons in Silver Nanowires

“…9,10 Apart from their waveguiding properties, studied extensively by near-field 10,13 and fluorescence-based imaging techniques, [26][27][28] coupled NW structures have been shown to exhibit device functionalities such as nanoscale routers, modulators and logic elements. 12,29 Despite reduced radiative losses, SPPs in chemically prepared NWs still suffer from absorptive losses (on the order of -0.4 dB µm -1 at 800 nm) because of strong confinement. 27 These losses represent an impediment toward the realization of integrated plasmonic circuitry.…”