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Surface plasmon polaritons (SPPs) give an opportunity to break the diffraction limit and design nanoscale optical components, however their practical implementation is hindered by high ohmic losses in a metal. Here, we propose a novel approach for efficient SPP amplification under electrical pumping in a deep-subwavelength metal-insulator-semiconductor waveguiding geometry and numerically demonstrate full compensation for the SPP propagation losses in the infrared at an exceptionally low pump current density of 0.8 kA/cm$^2$. This value is an order of magnitude lower than in the previous studies owing to the thin insulator layer between a metal and a semiconductor, which allows injection of minority carriers and blocks majority carriers reducing the leakage current to nearly zero. The presented results provide insight into lossless SPP guiding and development of future high dense nanophotonic and optoelectronic circuits., Comment: 5 figures

The development of sensing interfaces can significantly improve the performance of biological sensors. Graphene oxide provides a remarkable immobilization platform for surface plasmon resonance (SPR) biosensors due to its excellent optical and biochemical properties. Here, we describe a novel sensor chip for SPR biosensors based on graphene-oxide linking layers. The biosensing assay model was based on a graphene oxide film containing streptavidin. The proposed sensor chip has three times higher sensitivity than the carboxymethylated dextran surface of a commercial sensor chip. Moreover, the demonstrated sensor chips are bioselective with more than 25 times reduced binding for nonspecific interaction and can be used multiple times. We consider the results presented here of importance for any future applications of highly sensitive SPR biosensing.

A mechanism of generation of coherent terahertz electromagnetic radiation upon irradiation of a nanostructured metal surface by femtosecond laser pulses is proposed. The mechanism is based on the stimulated coherent radiation of electrons emitted from the metal surface and filling hollows in the periodic nanostructure.

We propose a very efficient approach for amplification of surface plasmon polaritons (SPPs) in a nanoscale waveguiding geometry with strong (∼λ/10) mode confinement. The implemented scheme of electric pumping is based on a single-heterostructure Schottky-barrier diode and has been numerically shown to ensure full compensation of the SPP propagation losses at wavelengths around 3 μm and, moreover, to provide net SPP gain. The presented concept creates the backbone for the implementation of highly integrated large-scale hybrid electronic-plasmonic circuits operating at extremely high speeds and opens the prospects for the realization of integrated coherent SPP sources.

The system of the two same, placed side-by-side and double clamped single-walled carbon nanotubes with metallic conductivity in the electromagnetic field of modulated and non-modulated terahertz radiation is considered. Forced oscillations of the carbon nanotubes electron plasma are calculated. The lumped parameters of the mechanical resonators that the nanotubes represent by themselves are determined. It is shown that the considered system of the nanotubes can serve as a detector of modulated terahertz radiation. The responsivity of the detector is estimated. The threshold value of the electric field amplitude of the incoming monochromatic terahertz radiation, above which the self-excitation of the nanotube mechanical resonators occurs is estimated.

We proposed a novel scheme of AM demodulator of terahertz radiation modulated by megahertz or gigahertz signals. Demodulator model is based on the nano-electromechanical system with the sufficiently narrow graphene nanoribbon as a mechanically moving part. Motion of a nanoribbon is supported by the electromagnetic ponderomotive force appearing due to the plasmon resonance exited in the system. Using developed model we obtained that the proposed demodulator has a number of advantages such as higher output signal and higher modulation frequency of incoming radiation in comparison with the previously proposed demodulators of terahertz radiation.

We propose a novel scheme of surface plasmon polariton (SPP) amplification by stimulated emission of radiation. It is based on a minority carrier injection in an Au/InAs Schottky diode. The proposed amplifier is electrically pumped and has a planar structure. Therefore, it is very compact and can be coupled easily to plasmonic waveguides.

We propose a novel technique of detection of ultrashort and few-cycle light pulses with a plasmonic nanocavity that is based on the extremely-slow-energy-velocity mode of the insulator-insulator-metal waveguide. We characterize the cavity analytically and demonstrate how it works using the FDTD method.

Effective excitation of the micro- and nanometer-size resonators has number of applications at various fields of science and technology. In particular, they include wireless telecommunication technologies [1], high sensitivity measuring systems [2], quantum information processing devices [3]. At the present report we consider the mechanical cantilever oscillations parametric excitation that serves as the gate electrode of a high electron mobility transistor (HEMT). The parametric coupling between the mechanical resonator (cantilever) and the oscillations of two-dimensional electron gas (2DEG) with high electron mobility is considered. In the capacity of the mechanical resonator a clamped nanobeam or a carbon nanotube might be used. 2DEG can arise in GaAs/AlGaAs heterostructures on the basis of which high electron mobility transistors (HEMT) are produced. Previously number of authors investigated the influence of the parametric coupling between mechanical and optical resonators [4, 5]. At our recent work [6] we proposed the uniform approach to such problems that is based on the lumped parameters method and the reduction of the parametric instability occurrence conditions question to the pure mathematical problem or the numerical solution of the certain system of second-order ODEs.

We propose a novel scheme of the semiconductor surface plasmon amplifier. It is based on a minority carrier injection in a metal‐insulator‐semiconductor diode. The principle of operation is as follows. Excess electrons and holes recombine radiatively and emit photons. If the difference between quasi‐Fermi levels exceeds the bandgap, the surface plasmon plasmon polariton (SPP) is amplified. A compact size and a planar structure of the amplifier allow to utilize it in integrated optical circuits and couple it easily to passive plasmonic devices. Moreover, the proposed technique can be used to obtain sufrace plasmon lasing by analogy with semiconductor lasers.

Our nanomechanical system reveals both the mechanical resonance associated with the mechanical oscillations of the nanocantilever and the plasma resonances due to the surface plasmons. The system in question can exhibit a gigantic response (very high sensitivity) when the modulation and carrier frequencies coincide with the mechanical and plasma resonant frequencies, respectively [1, 2]. Relatively large amplitude of the nanocantilever mechanical oscillations under the effect of the averaged field at the combined resonance results in relatively strong displacement ac current between the nanocantilever and the metal surface. This ac current at the modulation frequency can serve as the detector output signal.

We propose a novel scheme of the plasmonic cavity. It is based on insulator‐metal‐insulator (IMI) waveguide of finite length. Surface plasmon polaritons (SPPs) guided by IMI structure can exhibit extremely small energy velocity and thus the losses are determined mainly by the properties of the material used rather than the geometry of the cavity. Accordingly, we should care only about the metal film thicknesses and the purity of the metal and may not take into account the length of the cavity that simplifies the fabrication process. Moreover, it is possible to design nanocavity with all dimensions less than the wavelength of light. Using analytical and numerical techniques (FDTD method), we obtain the quality factor and other parameters of such cavities.

We develop a device model for p-i-n tunneling transit-time diodes based on graphene single- and multiple-layer structures operating at the reverse bias voltages. The model of the graphene tunneling transit-time diode (GTUNNETT) accounts for the features of the interband tunneling generation of electrons and holes and their ballistic transport in the device i-section, as well as the effect of the self-consistent electric field associated with the self-consistent charges of propagating electrons and holes. Using the developed model, we calculate the dc current-voltage characteristics and the ac frequency-dependent admittance as functions of the GTUNNETT structural parameters, in particular, the number of graphene layers.

We develop a device model for p-i-n tunneling transit-time diodes based on single- and multiple graphene layer structures operating at the reverse bias voltages. The model of the graphene tunneling transit-time diode (GTUNNETT) accounts for the features of the interband tunneling generation of electrons and holes and their ballistic transport in the device i-section, as well as the effect of the self-consistent electric field associated with the charges of propagating electrons and holes. Using the developed model, we calculate the dc current-voltage characteristics and the small-signal ac frequency-dependent admittance as functions of the GTUNNETT structural parameters, in particular, the number of graphene layers and the dielectric constant of the surrounding media. It is shown that the admittance real part can be negative in a certain frequency range. As revealed, if the i-section somewhat shorter than one micrometer, this range corresponds to the terahertz frequencies. Due to the effect of the self-consistent electric field, the behavior of the GTUNNETT admittance in the range of its negativity of its real part is rather sensitive to the relation between the number of graphene layers and dielectric constant. The obtained results demonstrate that GTUNNETTs with optimized structure can be used in efficient terahertz oscillators., Comment: 8 pages, 9 figures

We propose a resonant detector of terahertz radiation modulated by megahertz or gigahertz signals. The detector is based on mechanically floating carbon nanotubes (CNTs), suspended over an insulator. The device operation is associated with the excitation of both plasma and mechanical oscillations in CNTs resulting in an ac displacement current between them. This current plays the role of the detector output signal. Using the proposed device model, we find that the frequency dependence of the detector responsivity exhibits a sharp peak at the combined plasma-mechanical resonance and estimate its maximum value.

We propose a novel scheme of surface plasmon polariton (SPP) amplification that is based on a minority carrier injection in a Schottky diode. This scheme uses compact electrical pumping instead of bulky optical pumping. Compact size and a planar structure of the proposed amplifier allow one to utilize it in integrated plasmonic circuits and couple it easily to passive plasmonic devices. Moreover, this technique can be used to obtain surface plasmon lasing.

Existence conditions of backward waves and waves with zero group velocity in insulator–metal–insulator (IMI) structures are obtained and expressions for the group velocity of the surface plasmon polariton (SPP) are derived. We consider the general case when the two insulator half-spaces may be identical or different. The effect of losses on dispersion curves and values of the energy velocity is analyzed. The obtained equations are used for a characterization and a detailed study of backward waves in thin silver film waveguides.

Using the coupled-mode theory, we study the transmission of surface plasmon polaritons (SPPs) guided by a thin metal film through an array of N identical nanowires, which are parallel to each other and to the surface of the metal film. By varying the parameters of the nanowire array, one can control the intensity of the transmitted SPP. Furthermore, we propose a novel mechano-optical modulation technique. The intensity of the transmitted SPP is modulated by changing the distance between the nanowire array and the metal film. The modulation frequency is in the kilohertz or megahertz range, owing to the unique mechanical properties of nanowires.