Plasmonic amplification and suppression in nanowaveguide coupled to gain-assisted high-quality plasmon resonances

We theoretically study transmission in nanowaveguide coupled to high-quality plasmon resonances for which the metal loss is overcompensated by gain. The on-resonance transmission can vary widely from lower than --20dB to higher than 20dB for a range of gain coefficient. A reversible transition between the high-quality amplification and the suppression can be induced by a quite small change of gain coefficient for a moderately increased distance between the waveguide and the resonator. It is expected that in practice a small change of gain coefficient can be made by flexibly controlling pumping rate or utilizing nonlinear gain. Additionally, based on the frequency-dependant model for gain-transition susceptibility, it is shown that the wide variation of the on-resonance transmission can also be observed for defferent detuning of the gain-transition line-center. Such a widely controllable on-resonance transmission is promising for applications such as well-controlled lumped amplification of surface plasmon-polariton as well as plasmonic switching.Comment: submitted to Laser Physics Letter

Third-order nonlinearity by the inverse Faraday effect in planar magnetoplasmonic structures

We predict a new type of ultrafast third-order nonlinearity of surface plasmon polaritons (SPP) in planar magneto-plasmonic structures caused by the inverse Faraday effect (IFE). Planar SPPs with a significant longitudinal component of the electric field act via the IFE as an effective transverse magnetic field. Its response to the plasmon propagation leads to strong ultrafast self-action which manifests itself through a third-order nonlinearity. We derive a general formula and analytical expressions for the IFE-related nonlinear susceptibility for two specific planar magneto-plasmonic structures from the Lorentz reciprocity theorem. Our estimations predict a very large nonlinear third-order nonlinear susceptibility exceeding those of typical metals such as gold

Micro-joule sub-10-fs VUV pulse generation by MW pump pulse using highly efficient chirped-four-wave mixing in hollow-core photonic crystal fibers

We theoretically study chirped four-wave mixing for VUV pulse generation in hollow-core photonic crystal fibers. We predict the generation of sub-10-fs VUV pulses with energy of up to hundreds of microjoule by broad-band chirped idler pulses at 830 nm and MW pump pulses with narrow-band at 277 nm. MW pump could be desirable to reduce the complexity of the laser system or use a high repetition rate-laser system. The energy conversion efficiency from pump pulse to VUV pulse reaches to 30%. This generation can be realized in kagome-lattice hollow-core PCF filled with noble gas of high pressure with core-diameter less than 40 micrometers which would enable technically simple or highly efficient coupling to fundamental mode of the fiber

Generating Functional in String Field Theory

In our paper, we introduce a path integral of general functional field in order to build the path integral formalism in string field theory from the fact that a string field is a functional field, and describe a method for calculating it in the case of "Gauss-type". We also obtain the generating functional of an open bosonic string and the corresponding Feynman diagram

Classical Equation of Electromagnetic Field in the Higgs Boson Field and Estimation on the Static Electrical Polarizability of Leptons

In our paper we derived the classical motion equation of electromagnetic field in space with Higgs field and by means of it discussed the distributions of charge and current formed when the static electrical and magnetic fields are interacting with the spherically symmetrical Higgs field, and predicted the electrical polarizability of electron

Study on the Thickness Change of Nickel-Plated Layer in Fabrication of the Silver Hollow Nickel Waveguides by the Outer-Coating Method of the Liquid Phase Process

A metallic hollow waveguide is promising fiber for the delivery of laser radiation. Thickness of the nickel plated layer for supporting of the waveguide in fabrication of a dielectric coated silver hollow nickel waveguide is very important factor. In this paper, the change characteristic in the thickness of the nickel plated layer along the length of the silver coated glass mandrel during fabricating the silver hollow nickel waveguide by the outer-coating method of the liquid phase process has been studied both experimentally and analytically. Waveguides with uniform thickness of the nickel plated layer along the length of the silver coated glass mandrel have been fabricated

Intrinsic nonlinear response of surface plasmon polaritons

We offer a model to describe the intrinsic nonlinear response of surface plasmon polaritons (SPPs). Relation of the complex nonlinear coefficient of SPPs to the third-order nonlinear susceptibility of the metal is provided. As reported in a recent study, gold is highly lossy and simultaneously highly nonlinear due to interband absorption and interband thermo-modulation at a wavelength shorter than 700 nm. The effect of the high loss of the metal on the SPP nonlinear propagation is taken into account in our model. With the model we show difference in sign of real and imaginary parts between the nonlinear propagation coefficient and the nonlinear susceptibility of component material for the first time to our knowledge. Our model could have practical importance in studying plasmonic devices utilizing the nonlinear phase modulation and the nonlinear absorption of SPPs. For example, it allows one to extract the complex nonlinear susceptibility of gold through a measurement of SPP nonlinear propagation at the visible range

Effect of exchange interaction on electronic instabilities in the honeycomb lattice: A functional renormalization group study

The impact of local and nonlocal density-density interactions on the electronic instabilities in the honeycomb lattice is widely investigated. Some early studies proposed the emergence of interaction-induced topologically nontrivial phases, but recently, it was denied in several works including renormalization group calculations with refined momentum resolution. We use the truncated unity functional renormalization group to study the many-body instabilities of electrons on the half-filled honeycomb lattice, focusing on the effect of the exchange interaction. We show that varying the next-nearest-neighbor repulsion and nearest-neighbor exchange integral can lead to diverse ordered phases, namely, the quantum spin Hall, the spin-Kekul\'e, and some spin- and charge-density-wave phases. The quantum spin Hall phase can be induced by a combination of the ferromagnetic exchange and pair hopping interactions. Another exotic phase, the spin-Kekul\'e phase, develops in a very small region of the parameter space considered. We encounter the three-sublattice charge-density-wave phase in a large part of the parameter space. It is replaced by the incommensurate charge density wave when increasing the exchange integral. In order to reduce the computational effort, we derive the explicit symmetry relations for the bosonic propagators of the effective interaction and propose a linear-response-based approach for identifying the form factor of order parameter. Their efficiencies are confirmed by numerical calculations in our work.Comment: 13 pages, 6 figures, 1 Tabl

Ultracompact high-contrast magneto-optical disk resonator side-coupled to a plasmonic waveguide and switchable by an external magnetic field

Here we propose and study a novel type of plasmonic resonators based on a metal-insulator-metal waveguide and a side-coupled magneto-optical disk controlled by an external magnetic field. The wavenumber change and the transmission of surface-plasmon-polaritons (SPPs) can be tuned by altering the magnetic field and reversible on/off switching of the running SPP modes by a reversal of the direction of the external magnetic field is demonstrated. Resonant enhancement of the magneto-plasmonic modulation by more than 200 times leads to a modulation contrast ratio more than tenfold ratio (90-\%-modulation) keeping a moderate insertion loss within an optical bandwidth of hundreds of GHz. Numerical simulations confirm the predictions by the derived analytical formulas of a high-contrast magneto-plasmonic modulation by the submicron ultra-small disk resonator

Investigation of the Cubic Boron Nitride Nucleation under the High Pressure and the High Temperature

In this paper we have theoretically found the activation energy ($420.38kJ/mol$) for the transformation from hBN to cBN in the microscopic viewpoint. We have introduced an analytical formula representing the dependence of nucleus formation time on the activation energy, synthesis pressure and temperature. We have theoretically determined the boundary line of cBN nucleus formation region in the $P-T$ phase diagram on the basis of the diffusion mechanism of cBN nucleus formation. We have found that the cBN crystal nucleus formation time is less than $300ms$ by comparing of the theory and experiment