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Low-voltage broadband hybrid plasmonic-vanadium dioxide switches  [PDF]
Arash Joushaghani,Brett A. Kruger,Suzanne Paradis,David Alain,J. Stewart Aitchison,Joyce K. S. Poon
Physics , 2012, DOI: 10.1063/1.4790834
Abstract: Surface plasmon polaritons can substantially reduce the sizes of optical devices, since they can concentrate light to (sub)wavelength scales. However, (sub)wavelength-scale electro-optic plasmonic switches or modulators with high efficiency, low insertion loss, and high extinction ratios remain a challenge due to their small active volumes. Here, we use the insulator-metal phase transition of a correlated-electron material, vanadium dioxide, to overcome this limitation and demonstrate compact, broadband, and efficient plasmonic switches with integrated electrical control. The devices are micron-scale in length and operate near a wavelength of 1550 nm. The switching bandwidths exceed 100 nm and applied voltages of only 400 mV are sufficient to attain extinction ratios in excess of 20 dB. Our results illustrate the potential of using phase transition materials for highly efficient and ultra-compact plasmonic switches and modulators.
Plasmonic Demultiplexer and Guiding  [PDF]
Chenglong Zhao,Jiasen Zhang
Physics , 2010,
Abstract: Two-dimensional plasmonic demultiplexers for surface plasmon polaritons (SPPs), which consist of concentric grooves on a gold film, are proposed and experimentally demonstrated to realize light-SPP coupling, effective dispersion and multiple-channel SPP guiding. A resolution as high as 10 nm is obtained. The leakage radiation microscopy imaging shows that the SPPs of different wavelengths are focused and routed into different SPP strip waveguides. The plasmonic demultiplexer can thus serve as a wavelength division multiplexing element for integrated plasmonic circuit and also as a plasmonic spectroscopy or filter.
Kerr nonlinearity and plasmonic bistability in graphene nanoribbons  [PDF]
Thomas Christensen,Wei Yan,Antti-Pekka Jauho,Martijn Wubs,N. Asger Mortensen
Physics , 2015, DOI: 10.1103/PhysRevB.92.121407
Abstract: We theoretically examine the role of Kerr nonlinearities for graphene plasmonics in nanostructures, specifically in nanoribbons. The nonlinear Kerr interaction is included semiclassically in the intraband approximation. The resulting electromagnetic problem is solved numerically by self-consistent iteration with linear steps using a real-space discretization. We derive a simple approximation for the resonance shifts in general graphene nanostructures, and obtain excellent agreement with numerics for moderately high field strengths. Near plasmonic resonances the nonlinearities are strongly enhanced due to field enhancement, and the total nonlinearity is significantly affected by the field inhomogeneity of the plasmonic excitation. Finally, we discuss the emergence of a plasmonic bistability which exists for frequencies redshifted relative to the linear resonance. Our results offer new insights into the role of nonlinear interaction in nanostructured graphene and paves the way for experimental investigation.
Ultrafast Plasmonic Nanoantenna-ITO Hybrid Switches  [PDF]
Martina Abb,Otto L. Muskens
International Journal of Optics , 2012, DOI: 10.1155/2012/132542
Abstract: We present here a new type of device using nonlinear hybrid antenna-semiconductor (ITO) interaction. We observe a picosecond transient response from the antenna that cannot be explained by either pure ITO or antenna nonlinearities independently. We study the dependence of the hybrid interaction on several experimental parameters, including the polarization of excitation and detection. Nanoscale plasmonic components such as nanoantennas [1, 2] are of enormous interest for their capabilities of locally enhancing electromagnetic fields and controlling emission. Active control of such components will enable a new generation of tunable devices. We recently introduced a new concept of antenna switches relying on photoconductive loading of the gap between the arms of a dimer antenna [3]. Experimentally, modulation of localized plasmon modes has been achieved using the refractive index of liquid crystals [4]. Active tuning of the antenna gap has also been demonstrated using mechanical means, such as using stretchable elastomeric films [5] to reversibly engineer the distance between particle dimers. The temporal response of these changes is limited by the gap loading mechanisms that are used. As a potentially ultrafast implementation of our concept [3], we demonstrated experimentally picosecond all-optical control of a plasmonic nanoantenna on ITO, referred to as an nanoantenna-ITO hybrid [6]. For ITO, unity-order changes of the refractive index have been achieved [7] by applying an electric field. We have shown that optical pumping of ITO leads to a local reduction of the free-carrier density in the substrate. The transient nonlinear response of the antenna-ITO hybrid shows a redshift of the plasmon resonance, as opposed to transient bleaching on SiO2. Here, we present a detailed study of the response of antennas on 20?nm thick ITO film (low cond.), both with and without ITO cover layer. We find an effect for both perpendicular and parallel modes of the antenna, although the parallel mode shift is more pronounced, as well as a polarization dependence of the pump beam. Additionally, we look at the interaction of a larger cylindrical goldpad with the ITO surrounding it to further investigate the injection mechanism of fast electrons from the gold into the ITO. Nanoantennas were fabricated with e-beam lithography on low-conductivity (70–100?Ω/sq, 20?nm thick) and high-conductivity (8–12?Ω/sq, 120?nm thick) ITO substrates from Sigma-Aldrich using a bilayer of photoresist. After exposure and development, 25?nm of gold was deposited, followed by liftoff. To stay in
Graphene-based plasmonic switches at near infrared frequencies  [PDF]
J. S. Gomez-Diaz,J. Perruisseau-Carrier
Physics , 2013, DOI: 10.1364/OE.21.015490
Abstract: The concept, analysis, and design of series switches for graphene-strip plasmonic waveguides at near infrared frequencies are presented. Switching is achieved by using graphene's field effect to selectively enable or forbid propagation on a section of the graphene strip waveguide, thereby allowing good transmission or high isolation, respectively. The electromagnetic modeling of the proposed structure is performed using full-wave simulations and a transmission line model combined with a matrix-transfer approach, which takes into account the characteristics of the plasmons supported by the different graphene-strip waveguide sections of the device. The performance of the switch is evaluated versus different parameters of the structure, including surrounding dielectric media, electrostatic gating and waveguide dimensions.
Mechanism for graphene-based optoelectronic switches by tuning surface plasmon-polaritons in monolayer graphene  [PDF]
Yu. V. Bludov,M. I. Vasilevskiy,N. M. R. Peres
Physics , 2010, DOI: 10.1209/0295-5075/92/68001
Abstract: It is shown that one can explore the optical conductivity of graphene, together with the ability of controlling its electronic density by an applied gate voltage, in order to achieve resonant coupling between an external electromagnetic radiation and surface plasmon-polaritons in the graphene layer. This opens the possibility of electrical control of the intensity of light reflected inside a prism placed on top of the graphene layer, by switching between the regimes of total reflection and total absorption. The predicted effect can be used to build graphene-based opto-electronic switches.
Plasmonic nanoantennas as integrated coherent perfect absorbers on SOI waveguides for modulators and all-optical switches  [PDF]
Roman Bruck,Otto L. Muskens
Physics , 2013, DOI: 10.1364/OE.21.027652
Abstract: The performance of plasmonic nanoantenna structures on top of SOI wire waveguides as coherent perfect absorbers for modulators and all-optical switches is explored. The absorption, scattering, reflection and transmission spectra of gold and aluminum nanoantenna-loaded waveguides were calculated by means of 3D finite-difference time-domain simulations for single waves propagating along the waveguide, as well as for standing wave scenarios composed from two counterpropagating waves. The investigated configurations showed losses of roughly 1% and extinction ratios greater than 25 dB for modulator and switching applications, as well as plasmon effects such as strong field enhancement and localization in the nanoantenna region. The proposed plasmonic coherent perfect absorbers can be utilized for ultracompact all-optical switches in coherent networks as well as modulators and can find applications in sensing or in increasing nonlinear effects.
Determination of the Surface Plasmons Polaritons extraction efficiency from a self-assembled plasmonic crystal  [PDF]
Hugo Frederich,Fangfang Wen,Julien Laverdant,Willy Daney de Marcillac,Catherine Schwob,Laurent Coolen,Agnès Ma?tre
Physics , 2013,
Abstract: We experimentally measure and analytically describe the fluorescence enhancement obtained by depositing CdSe/CdS nanocrystals onto a gold plasmonic crystal, a two-dimensional grating of macroscopic size obtained by gold deposition on a self-assembled opal. We show evidences of nanocrystals near-field coupling to the gold Surface Plasmons Polaritons (SPP) followed by grating-induced SPP re-emission to far-field. We develop a theoretical framework and an original method in order to evaluate, from photoluminescence experiments, the SPP extraction efficiency of a grating.
Second-Harmonic Generation of Spoof Surface Plasmon Polaritons Using Nonlinear Plasmonic Metamaterials  [PDF]
Hao Chi Zhang,Yifeng Fan,Jian Guo,Xiaojian Fu,Lianming Li,Cheng Qian,Tie Jun Cui
Physics , 2015,
Abstract: The second harmonic generation is one of the most important applications of nonlinear effect, which has attracted great interests in nonlinear optics and microwave in the past decades. To the best of our knowledge, however, generating the second harmonics of surface plasmon polaritons (SPPs) has not been reported. Here, we propose to generate the second harmonics of spoof SPPs with high efficiency at microwave frequencies using subwavelength-scale nonlinear active device integrated on specially designed plasmonic waveguides, which are composed of two ultrathin corrugated metallic strips printed on the top and bottom surfaces of a thin dielectric slab anti-symmetrically. We show that the plasmonic waveguide supports broadband propagations of spoof SPPs with strong subwavelength effect, whose dispersion property can be controlled by changing the geometrical parameters. By loading the nonlinear device made from semiconductors to the intersection of two plasmonic waveguides with different corrugation depths, we experimentally demonstrate the efficient generation of second-harmonic SPPs in broad frequency band. The proposed second-harmonic generator can be directly used as SPP frequency multiplier, and the proposed method can be extended to achieve high-order harmonics and produce SPP mixers, which are essential to SPP integrated circuits and systems.
Plasmonic crystals for ultrafast nanophotonics: Optical switching of surface plasmon polaritons  [PDF]
M. Pohl,V. I. Belotelov,I. A. Akimov,S. Kasture,A. S. Vengurlekar,A. V. Gopal,A. K. Zvezdin,D. R. Yakovlev,M. Bayer
Physics , 2011, DOI: 10.1103/PhysRevB.85.081401
Abstract: We demonstrate that the dispersion of surface plasmon polaritons in a periodically perforated gold film can be efficiently manipulated by femtosecond laser pulses with the wavelengths far from the intrinsic resonances of gold. Using a time- and frequency- resolved pump-probe technique we observe shifting of the plasmon polariton resonances with response times from 200 to 800 fs depending on the probe photon energy, through which we obtain comprehensive insight into the electron dynamics in gold. We show that Wood anomalies in the optical spectra provide pronounced resonances in differential transmission and reflection with magnitudes up to 3% for moderate pump fluences of 0.5 mJ/cm^2.
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