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To meet the demand of delivering ever-increasing Internet traffic, optical network must response by increasing its transmission capacity. Since transmission capacity of an individual fiber is still well exceed the capacity of transmitters (TXs) and receivers (RXs), wavelength-division multiplexing (WDM), in which many TXs and RXs at the transmitting ends of a fiber are used to send and receive many signals, becomes the necessary technology for increasing the transmission capacity of each link of an optical network. This trend, however, demands for increasing density not only the TXs and RXs, but all other components at the sending and receiving ends of communications links. As the number of wavelengths in WDM configuration getting greater, the number of all these components that must be placed on one board has to increase too; hence, the density of packaging comes to micro- and even nano-scale. The TXs and RXs are produced in arrays on a chip quite similar to production of VLSI electronic circuits. At that scale, traditional optical operations used today in an optical-communications technology, such as launching light into optical fiber from TXs and directing light from optical fiber into RXs, multiplexing and demultiplexing individual channels (wavelengths), and electro-optical (E/O) and opto-electrical (O/E) conversions become problems primarily because of the diffraction limit. The problems associated with the diffraction limit are particularly acute for optical interconnects. One of the possible solutions to all these—and some other—problems could be the use of plasmonics. In the last years, the optical-communications industry shows a great interest in developing this topic, as the growing number of publications and practical results can attest.

This paper consists of two parts. The first part reviews the current trends in application of plasmonics in optical communications and the second part discusses the theoretical foundation of the proposed WDM demultiplexer and offers the scheme of possible implementation of the device.

Sensing applications of THz technology include applications for space exploration, detection of concealed objects, explosive identification, and THz cancer detection. This paper will review these and other emerging applications and existing and potential THz sources and detectors, including photonic and electronic THz devices, such as plasmonic field effect transistors capable of detecting and emitting THz radiation. Plasma wave electronics devices demonstrated THz detection using GaAs-based and GaN-based HEMTs, Si MOS, SOI, and FINFETs and FET arrays. This technology has potential to become a dominant THz electronics technology.

Terahertz (THz) sensing technology enables 6G communication, detection of biological and chemical hazardous agents, cancer detection, monitoring of industrial processes and products, and detection of mines and explosives. THz sensors support security in buildings, airports, and other public spaces. They found important applications in radioastronomy and space research and, more recently, in Artificial Intelligence-driven THz sensing of MMICs and VLSI. Exploding demand for data transfers will require using the 300 GHz band after 2028 or even before and will make the deployment of THz sensing electronics inevitable. This paper discusses the new physics of THz sensing and THz sensing devices. It also reviews the THz sensing market, and key THz sensor companies.

We report on the plasmonic properties of silver-coated dielectric nanocylinders arranged according to an unconventional geometrical representation called Pascal's triangle. We performed numerical simulations to calculate the extinction spectrum and identify the collective optical modes in the geometry. For resonant excitation at 410 nm, we found pronounced field localization (50 nm) at the center of the Pascal triangle. Further, we studied the near-field intensity as a function of experimentally-relevant variables such as excitation wavelength, angle of incidence and dielectric constant of the core material. Our analysis revealed pronounced difference between near-field intensities for resonant and non-resonant excitation wavelength at various angle of incident radiation; and an increment in near-field intensity at excitation wavelengths greater than 600 nm, with increase in dielectric constant of core material. Our study has relevance in development of substrates with tunable electromagnetic hot-spots for on-chip plasmonics.

In the last few years, plasmonics has attracted much attention and has been included in the principal domains of nanophotonics that can manage optical fields at the nanodimension level. Its exquisite characteristic is to increase the electromagnetic fields at the nanometer scale particularly in the solar cell. In the plasmonic discipline, noble metals used as nanoparticles in which the density of the electron gas which oscillates at surface plasmon frequency at that time also enhances absorption via scattering. So the usage of plasmonics in solar cells offers better possibility of improving the performance through absorption, because the optical spectrum loss is principal as a part of the overall loss for the solar photovoltaic cell. So we investigated the impact of the nanoparticle size for the enhancement of extinction in terms of absorption and scattering by using surface plasmon resonance, and additionally studied the finite-difference time domain (FDTD)-based proposed model and found various plasmonic fields components and characterized optical enhancement in the plasmonic thin film solar cell.

In this paper, surface plasmons polariton propagation and manipulation is reviewed in the context of experiments and modeling of optical images. We focus our attention in the interaction of surface plasmon polaritons with arrays of micro-scatereres and nanofabricated structures. Numerical simulations and experimental results of different plasmonic devices are presented. Plasmonic beam manipulation opens up numerous possibilities for application in biosensing, nanophotonics, and in general in the area of surface optics properties.

We developed a fast numerical algorithm for solving the three-dimensional vectorial Helmholtz equation that arises in electromagnetic scattering problems. The algorithm is based on electric field integral equations and is essentially a boundary element method. Nyström's quadrature rule with a triangular grid is employed to linearize the integral equations, which are then solved by using a right-preconditioned iterative method. We apply the fast multipole technique to accelerate the matrix-vector multiplications in the iterations. We demonstrate the broad applications and accuracy of this method with practical examples including dielectric, plasmonic and metallic objects. We then apply the method to investigate the plasmonic properties of a silver torus and a silver split-ring resonator under the incidence of an electromagnetic plane wave. We show the silver torus can be used as a trapping tool to bind small dielectric or metallic particles.

Plasmonic nanostructures hold immense potential for structure-based color engineering at the subwavelength length scale. In this paper, we will review representative works that demonstrate promising strategies to exploit the rich mechanisms of surface plasmons for color engineering across the visible spectrum. By varying the structural design and material composition of plasmonic nanostructures through chemical synthesis or lithography, these approaches can achieve highly controllable and tunable colors for a wide variety of applications. We will also critically discuss the applications of these state-of-the-art technologies in color filtering, color printing and color-based chemical and biological sensing.

The inherent thinness of two-dimensional 2D materials limits their efficiency of light-matter interactions and the high loss of noble metal plasmonic nanostructures limits their applicability. Thus, a combination of 2D materials and plasmonics is highly attractive. This review describes the progress in the field of 2D plasmonics, which encompasses 2D plasmonic materials and hybrid plasmonic-2D materials structures. Novel plasmonic 2D materials, plasmon-exciton interaction within 2D materials and applications comprising sensors, photodetectors and, metasurfaces are discussed.

The hydrodynamic model of the electron transport in the channel of a nanoscale field effect transistors predicts that three different electron transport regimes – collision-dominated, ballistic, and viscosity dominated – determine the ultimate response time of the semiconductor device depending on its length, momentum relaxation time, and viscosity. The characteristic response times of ultra-short channel transistors are in the subpicosecond range. We now report on a new measurement technique with a greatly enhanced sensitivity using optical band-to-band pulses with a controlled delay. The measurements using this new electro-optic sampling and hydrodynamic modeling reveal the ultra-fast transistor plasmonic response at the time scale much shorter than the electron transit time.

To meet the demand of delivering ever-increasing Internet traffic, optical network must response by increasing its transmission capacity. Since transmission capacity of an individual fiber is still well exceed the capacity of transmitters (TXs) and receivers (RXs), wavelength-division multiplexing (WDM), in which many TXs and RXs at the transmitting ends of a fiber are used to send and receive many signals, becomes the necessary technology for increasing the transmission capacity of each link of an optical network. This trend, however, demands for increasing density not only the TXs and RXs, but all other components at the sending and receiving ends of communications links. As the number of wavelengths in WDM configuration getting greater, the number of all these components that must be placed on one board has to increase too; hence, the density of packaging comes to micro- and even nano-scale. The TXs and RXs are produced in arrays on a chip quite similar to production of VLSI electronic circuits. At that scale, traditional optical operations used today in an optical-communications technology, such as launching light into optical fiber from TXs and directing light from optical fiber into RXs, multiplexing and demultiplexing individual channels (wavelengths), and electro-optical (E/O) and opto-electrical (O/E) conversions become problems primarily because of the diffraction limit. The problems associated with the diffraction limit are particularly acute for optical interconnects. One of the possible solutions to all these—and some other—problems could be the use of plasmonics. In the last years, the optical-communications industry shows a great interest in developing this topic, as the growing number of publications and practical results can attest.

This paper consists of two parts. The first part reviews the current trends in application of plasmonics in optical communications and the second part discusses the theoretical foundation of the proposed WDM demultiplexer and offers the scheme of possible implementation of the device.

Sensing applications of THz technology include applications for space exploration, detection of concealed objects, explosive identification, and THz cancer detection. This paper will review these and other emerging applications and existing and potential THz sources and detectors, including photonic and electronic THz devices, such as plasmonic field effect transistors capable of detecting and emitting THz radiation. Plasma wave electronics devices demonstrated THz detection using GaAs-based and GaN-based HEMTs, Si MOS, SOI, and FINFETs and FET arrays. This technology has potential to become a dominant THz electronics technology.