Plasmonics|15 Article(s)
Sequential trapping of single nanoparticles using a gold plasmonic nanohole array
Xue Han, Viet Giang Truong, Prince Sunil Thomas, and Síle Nic Chormaic
Photonics Research
  • Publication Date: Oct. 01, 2018
  • Vol. 6, Issue 10, 10000981 (2018)
E-shaped wideband plasmonic nantennas with linear and dual-linear polarizations
Mohamed H. El Sherif, Mohamed H. Bakr, and Ezzeldin A. Soliman
In this paper we present a novel nanoantenna (nantenna) design for energy harvesting. The nantenna has an “E” shape and is placed on a SiO2 substrate. Its operation is based on the excitation of surface plasmon polaritons through the gold arms of the E shape. By varying the lengths and widths of the arms, two overlapping working bandwidths can be achieved. This results in a wideband behavior characterized by a full width at half-maximum of about 2.2 μm centered around 3.6 μm. Two orthogonal E nantennas are placed perpendicular to each other to realize a dual-polarized nantenna. This nantenna can receive the two incident polarizations at two separate gap locations with very high isolation. The proposed structure can be used in several energy harvesting applications, such as scavenging the infrared heat from the Earth and other hot objects, in addition to optical communications.crystals;Subwavelength structures, nanostructures;Resonance
Photonics Research
  • Publication Date: Jun. 05, 2015
  • Vol. 3, Issue 4, 04000140 (2015)
Understanding localized surface plasmon resonance with propagative surface plasmon polaritons in optical nanogap antennas
Hongwei Jia, Fan Yang, Ying Zhong, and Haitao Liu
The plasmonic nanogap antenna is an efficient radiating or receiving optical device. The resonance behavior of optical antennas is commonly attributed to the excitation of a localized surface plasmon resonance (LSPR), which can be theoretically defined as the quasi-normal mode (QNM). To clarify the physical origin of the LSPR, we build up an analytical model of the LSPR by considering a multiple scattering process of propagative surface plasmon polaritons (SPPs) on the antenna arms. The model can comprehensively reproduce the complex eigenfrequency and the field distribution of QNMs of the antenna, unveiling that the LSPR arises from a Fabry–Perot resonance of SPPs. By further applying the complex pole expansion theorem of meromorphic functions, the field of the antenna under illumination by a nearby dipole emitter can be analytically expanded with QNMs, which well predicts the frequency response of the enhancement factor of radiation. The present model establishes explicit relations between the concepts of the LSPR and the propagative SPP and integrates the advantages of the Fabry–Perot and QNM formalisms of nanogap antennas.
Photonics Research
  • Publication Date: Nov. 15, 2016
  • Vol. 4, Issue 6, 06000293 (2016)
Low cross-talk, deep subwavelength plasmonic metal/insulator/metal waveguide intersections with broadband tunability
Tae-Woo Lee, Da Eun Lee, Young Jin Lee, and Soon-Hong Kwon
Photonics Research
  • Publication Date: Nov. 15, 2016
  • Vol. 4, Issue 6, 06000272 (2016)
Active macroscale visible plasmonic nanorod self-assembled monolayer
Yue Li, Jian Li, Taixing Huang, Fei Huang, Jun Qin, Lei Bi, Jianliang Xie, Longjiang Deng, and Bo Peng
Although plasmonic nanostructure has attracted widespread research interest in recent years, it is still a major challenge to realize large-scale active plasmonic nanostructure operation in the visible optical frequency. Herein, we demonstrate a heterostructure geometry comprising a centimeter-scale Au nanoparticle monolayer and VO2 films, in which the plasmonic peak is inversely tuned between 685 nm and 618 nm by a heating process since the refractive index will change when VO2 films undergo the transition between the insulating phase and the metallic phase. Simultaneously, the phase transition of VO2 films can be improved by plasmonic arrays due to plasmonic enhanced light absorption and the photothermal effect. The phase transition temperature for Au/VO2 films is lower than that for bare VO2 films and can decrease to room temperature under the laser irradiation. For light-induced phase transition of VO2 films, the laser power of Au/VO2 film phase transition is ~28.6% lower than that of bare VO2 films. Our work raises the feasibility to use active plasmonic arrays in the visible region.
Photonics Research
  • Publication Date: Apr. 18, 2018
  • Vol. 6, Issue 5, 05000409 (2018)
Enhancing plasmonic trapping with a perfect radially polarized beam
Xianyou Wang, Yuquan Zhang, Yanmeng Dai, Changjun Min, and Xiaocong Yuan
Strong plasmonic focal spots, excited by radially polarized light on a smooth thin metallic film, have been widely applied to trap various micro- and nano-sized objects. However, the direct transmission part of the incident light leads to the scattering force exerted on trapped particles, which seriously affects the stability of the plasmonic trap. Here we employ a novel perfect radially polarized beam to solve this problem. Both theoretical and experimental results verify that such a beam could strongly suppress the directly transmitted light to reduce the piconewton scattering force, and an enhanced plasmonic trapping stiffness that is 2.6 times higher is achieved in experiments. The present work opens up new opportunities for a variety of research requiring the stable manipulations of particles.
Photonics Research
  • Publication Date: Aug. 08, 2018
  • Vol. 6, Issue 9, 09000847 (2018)
Room temperature optical mass sensor with an artificial molecular structure based on surface plasmon optomechanics
Jian Liu, and Ka-Di Zhu
We propose an optical weighing technique with a sensitivity down to a single atom through the coupling between a surface plasmon and a suspended graphene nanoribbon resonator. The mass is determined via the vibrational frequency shift on the probe absorption spectrum while the atom attaches to the nanoribbon surface. We provide methods to separate out the signals of the ultralow frequency vibrational modes from the strong Rayleigh background, first based on the quantum coupling with a pump-probe scheme. Owing to the spectral enhancement in the surface plasmon and the ultralight mass of the nanoribbon, this scheme results in a narrow linewidth (~GHz) and ultrahigh mass sensitivity (~30 yg). Benefitting from the low noises, our optical mass sensor can be achieved at room temperature and reach ultrahigh time resolution.
Photonics Research
  • Publication Date: Aug. 09, 2018
  • Vol. 6, Issue 9, 09000867 (2018)