Generation of a photonic nanojet with a slightly subwavelength waist at the back side of a dielectric microsphere or microcylinder impinged by a plane wave has recently shown that the near-field effects may hold not only inside the dielectric microparticle, but also outside it. In this paper we explain how to drastically increase the external near-field effect. For it one has to replace a plane wave

We theoretically investigated the localization and switching properties of surface waves that appear at the interface between the homogeneous medium and a semi-infinite one-dimensional photonic crystal in the presence of chiral metamaterial as a cap layer, using the transfer matrix method. The one-dimensional photonic crystal is made of alternating layers of right-handed and dispersive left-handed

In this work, a high Q-factor photonic crystal microring resonator (PC-MRR) based pressure sensor is reported. This sensor is designed based on SOI technology. The modelling and analysis of integrated optical (IO) resonator and mechanical diaphragm are carried out by using the Finite Element Method (FEM) and the Finite-Difference Time-Domain (FDTD) method respectively. The sensor consists of IO hexagonal

In magnetic resonance imaging, a birdcage coil is the most commonly used volumetric resonator creating a highly homogeneous radiofrequency magnetic field in a conductive sample. An artificial magnetic radiofrequency shield was recently shown to improve the magnetic field amplitude per unit power (transmit efficiency) of a preclinical birdcage coil by reducing the intrinsic losses in the coil and increasing

To realize wavelength division multiplexing for high-capacity optical communications, we theoretically investigate the properties of a photonic crystal waveguide structure in which a row of air holes is displaced by a/2 (a is the lattice constant). We calculate transmission loss and coupling efficiency to circular defect cavities of this waveguide structure, which we call an orthogonal lattice waveguide

Noble metal material, size, period and position are key parameters to affect optical absorption property of perovskite thin film, which was numerically investigated in this paper by finite element method. It demonstrates that Al nanoparticles show larger enhancement ability of light absorption than that of Au and Ag under AM1.5 illumination with the same geometry parameter. The light absorption enhancement

One-dimensional structures of non-Hermitian plasmonic metallic nanospheres are studied in this paper. For a single sphere, solving Maxwell's equations results in quasi-stationary eigenmodes with complex quantized frequencies. Coupled mode theory is employed in order to study more complex structures. The similarity between the coupled mode equations and the effective non-Hermitian Hamiltonians governing

In this article, we propose the design and analysis of all-dielectric metasurface based tunable optical modulator. The metasurface structure consists of split silicon arcs mounted over the indium tin oxide layer and the silica substrate. The nematic liquid crystal is used for tuning the Fano resonance peak of the metasurface and is filled between two indium tin oxide layers. The numerical investigation

In this paper we aim to propose and design an all optical analog to digital converter for generating 2-bit Gray codes from the optical intensity of the input signal. Two nonlinear resonant rings will be used for realizing the proposed structure. These nonlinear resonators should be designed such that they can drop optical waves at different optical intensity ranges. The nonlinear resonators will be

We report on tellurium nanorods as a new type of saturable absorber (SA)-induced four-wave-mixing to construct an all-fiber multi-wavelength passively Q-switched erbium-doped-fiber laser. This proposed material is prepared via a green method of nanorod synthesis. The results show that the SA device simultaneously generates seven wavelengths within 1592.4–1599.6 nm waveband and mode spacing of 1.2 nm

A hot-spot of high local field can be created between two closely placed metal nanoparticles and by irradiating them with an appropriate wavelength and polarization of incident light. The strength of the field at the gap between the particles is expected to get enhanced by several orders of magnitude higher than that of the applied field. Placing a semiconductor quantum dot or an analyte molecule at

We investigate a high-sensitivity plasmonic sensor that uses a hexagonal nanorod array metasurface with for identifying malignant hepatic metastases from healthy liver cells. This designed plasmonic metasurface has some advantages such as nanoscale dimensions, a high figure of merit and sensitivity to the refractive index, and insensitivity to the incident angle for 0° to 60°. With the 3D finite-difference

A three-dimensional electromagnetic field model has been developed to study the photon capture properties of gradient band-gap AlxGa1-xN nanomaterials with built-in electric field using COMSOL Multiphysics commercial software based on finite element numerical simulation. Based on the phototrapping mechanism and the concept of radial mode resonance absorption, we studied AlxGa1-xN nanomaterials with

The design, analysis, and simulation of a 1 × 2 decoder based on self-collimated beams was the aim of this work. The proposed structure consists of two-dimensional (2D) photonic crystals with their silicon rods in air. The device, of a relatively simple structure with a footprint of 228.71 μm2, comprises two inputs (I and Iref) and three outputs (Q1, Q2, and QI). It, furthermore, contains two beam

In this work, we combine Lithium Niobate on insulator with a silicon nitride layer to form strip-loaded waveguides that can take advantage of the strong nonlinear optical coefficients of lithium niobate and of the high refractive contrast and ease of processing of silicon nitride. We describe the design and fabrication of a Fabry-Perot cavity formed by Distributed Bragg Reflectors. We discuss the design

Fourier modal expansion techniques are very well suited for electromagnetic (EM) scattering in planar periodic stratified media. These techniques expand the transverse EM fields in Bloch modes in each strata unit-cell, but do not rigorously enforce EM boundary conditions at interior material interfaces which gives rise to slow convergence of the polarized S-matrix values with increasing Fourier series

This work investigates the effect of titanium dioxide (TiO2) nanostructures on the overall optical performance of gallium arsenide (GaAs) solar cells. The optical properties of three different TiO2 nanostructures shapes namely, cubic, spherical, and pyramidal are studied to minimize the reflectivity of GaAs substrates. The dimensions of these three nanoparticle-shapes are varied in the simulations

In this work we report on a light analysis system based on narrowband colloidal PbS quantum dot photodetectors. The proposed system is able to identify both the peak wavelength of a quasi-monochromatic radiation and the emission spectrum of an arbitrary light source, in the visible and near infrared spectral range, starting from photocurrent measurements of several photoconductive devices with different

In this work, we propose a graphene-based electro-absorption modulator design using an asymmetric plasmonic slot waveguide. Such asymmetric slot waveguide allows us to achieve a strong light-matter interaction with a large orientation match between the polarization of confined modal field and graphene plane. Thus, a significant change in total optical absorption and, hence, modulation efficiency is

A temperature sensor with a wide measurement range and high sensitivity is proposed and analyzed. It is based on a microstructured fiber (MSF) Sagnac interferometer. The air holes were filled with ethanol by a full filling method. Increase of the birefringence and the sensitivity of the proposed sensor can be achieved by moving the two air holes on the left and right sides of the core. For an MSF with

Symmetric and asymmetric quantum wells of ZnCdO structures grown on ZnO in non-polar orientations are investigated for their potential in THz emission due to the intersubband transitions between the subbands in the conduction band. The Schrödinger and Poisson equations are solved self-consistently for the square and step-barrier quantum wells of the Zn1−xCdxO layers for x up to 0.25. The results are

In this study, a multiple input/multiple output (MIMO) indoor communication system was developed using microstrip antennae based on a photonic crystal substrate, where the graphene load operated in the terahertz band. First, the characteristics of graphene were analyzed by determining the operating modes related to the chemical potential of graphene. Next, three MIMO antennae were designed and analyzed

A highly sensitive near-infrared vertical photodetector was fabricated by our sandwiching a lead sulfide (PbS) nanocrystal and poly(3-hexylthiophene) hybrid channel between a graphene source electrode and a Au drain electrode. The device showed excellent electric and photoresponse characteristics as a result of the strong near-infrared absorption of PbS nanocrystal, the ultrashort channel of the vertical

This paper proposed a novel structure to improve modulation bandwidth of light-emitting diode. The SiO2-ITO quasi-symmetrical waveguide structure and SiO2-Ag grating are used to enhance the internal quantum efficiency. The surface plasmons induced by Ag can effectively increase the spontaneous emission rate and carrier recombination lifetime. Diamond is used to improve the heat dissipation performance

We perform a theoretical study of light propagation properties in two-dimensional square photonic crystals following Bravais-Moiré patterns, paying particular attention to the influence of the transversal shape and the orientation of the dielectric scatters onto the width and position of photonic band gaps. In this sense, we have considered both square and triangular transversal geometries for the

An ultra-compact all-optical half-adder operating at 1550 nm on silicon-on-insulator is realized by a modular-inverse-design method which deconstruct the design of optical units with complicated functions to several devices with basic functions. The half adder is composed of five modules: two beam splitters, one hub, one XOR gate and one AND gate, all of which are designed by the same multi-objective

The two-dimensional (2D) heterostructure of black phosphorus (BP)–MXene shows great stability in liquid and gaseous environments. Sensitivity enhancement of a surface plasmon resonance (SPR) sensor utilizing BP and Ti3C2Tx MXene layer is proposed in this work. A CaF2 glass prism is considered as the coupling substrate and 2D Ti3C2Tx MXene as analyte interacting layer. The sensor’s performance is demonstrated

A plasmonic refractive index sensor based on a metal-insulator-metal waveguide coupled with a double concentric square ring resonator is proposed and analyzed both theoretically and numerically. The theoretical and the numerical results are based on the transmission-line model and the finite difference time domain method, respectively. The theoretical results agree well with the numerical ones. A maximum

Nonlinear metasurfaces that dynamically manipulate the phase of a passing light beam are of interest for a wide range of applications. The controlled operation of such devices requires accurate measurements of the optical transmission phase in both the linear and nonlinear regime, an experimentally challenging task. In this paper we show that this phase information can be extracted directly from simple

In this work, we introduce a four green-light wavelength splitter device, based on six slot-waveguide structures. Silica and gallium nitride materials were chosen for confining the green light inside the slot-waveguide area in a transverse magnetic field mode. The device functioned as a 1 × 4 demultiplexer, which demultiplexes wavelengths in the green-light band with wavelength range of 500–530 nm

We propose a novel analytical model for anisotropic multi-layer cylindrical structures containing graphene layers. The general structure is formed by the aperiodic repetition of a three-layer sub-structure, where a graphene layer with isotropic surface conductivity of σ is sandwiched between two adjacent magnetic materials. Each anisotropic material has permittivity and permeability tensors of ε̿ and

Plasmonic chemical and biological sensors have many advantages such as compact sizes and extremely high sensitivity. Biosensors based on plasmonic waveguides and resonators are one of the most attractive candidates for mobile and portable devices. In this work, we proposed a metal-insulator-metal waveguide semi-ring resonator loaded with nanodots periodically decorated in the cavity. The spectral characteristics

A new photonic crystal (PC) based 2×1 multiplexer, which composed of a Kerr nonlinear Fano resonance-based switching module and an adder module, is presented. In the proposed device, using a pump light power, it is possible to control the transmissions of the input signals into the output port. The performance of the proposed device is examined using the finite-difference time-domain (FDTD) method

In this paper, a new technique is proposed for designing stealthy radome, especially for normal incoming wave stealth. The proposed structure is composed of a band-pass FSS and one layer of polarization conversion arrays which are separated by a foam layer. An FSS-backed polarization conversion meta-surface (PCM) can be obtained. The FSS-backed PCM is capable of providing a second-order transmission

Plasmonics have allowed revolutionary progress in field of random lasers through improvement of the lasing property via surface plasmon resonance (SPR). However, localized surface plasmon resonance (LSPR) spectra of conventional metal nanostructures are too narrow to sufficiently cover both the absorption and emission spectra of dyes. Therefore, in this paper, we fabricate a typical Ag-TiO2 composite

The metasurface-based concept of a smart table for wireless power transfer (WPT) has been recently proposed and experimentally proven to be capable of transferring energy to 1 m with high efficiency. However, in reality, we usually encounter the need to transfer energy to several receivers and with the presence of various obstacles. Herein, we explore the capabilities of the smart table scenario in

In the present work, some optical properties related to intersubband transitions in finite depth asymmetric hyperbolic-type quantum wells are theoretically investigated. The use of a hyperbolic potential configuration would account for the actual – non abrupt – confinement potential in the heterostructure, in the case of modulated growing or when compositional diffusion across the interfaces turns

An ultrabroadband and compact square-lattice photonic crystal fiber polarization filter based on surface plasmon resonance is proposed. Four large air holes are introduced near the core to destroy the symmetry of the original fiber structure so that the resonance wavelengths of x- and y-polarized core modes can be well separated. The inner walls of two large air holes along the x polarization direction

A mirrored bilayer structure incorporating layers of Graphene and MoS2 is proposed here for Surface Plasmon Resonance (SPR) biosensing and its performance is evaluated numerically. Starting from the basic configuration, the structure with graphene and MoS2 layers is gradually developed for enhanced performance. Reflectance is the main considered parameter for performance analysis. A theoretical framework

Metal-organic frameworks (MOFs) represent a unique platform for fabrication of nanoparticles (NPs) of diverse composition and crystallinity. The growth of NPs from constituent parts of MOFs is usually initiated by external stimuli such as temperature, light and electron irradiation. Herein, the kinetics and NP growth mechanisms remain unexplored. Here, we utilized electron irradiation to initiate the

A six-port path-reconfigurable circulator based on Y-type plasma photonic crystals (PPC) has been proposed. By calculating and analyzing the transfer matrix equation of the transverse magnetic (TM) waves, it can be concluded that the anisotropy generated by the magnetized plasma enables the TM waves to produce elliptical polarization. Therefore, the plasma columns are introduced in the design of a

The design flexibility of Hollow-Core Photonic Crystal Fibres (HC-PCFs) is a significant feature that allows the fibres to achieve excellent optical properties. Changes in the design parameters of HC-PCFs used for gas sensing can affect their optical and gas flow properties. The aim of this paper is to investigate the performance of three HC-PCFs with different geometries (HC-800-02, HC-1550-02, HC-2000-01)

In this paper, we theoretically demonstrate a nanophotonic optical asymmetric transmission device (NOATD) for arbitrary linear polarization, which is composed of two two-dimensional (2D) square-lattice photonic crystals (PhCs) with different effective refractive indices. In this way, the NOATD achieves asymmetric transmission based on the generalized total reflection principle, which is able to realize

Optical analog to digital conversion is very important for implementing all-optical data processing systems. In this study, we designed an all-optical analog to digital converter using photonic crystal nonlinear ring resonators. The main goal of this study was to design an optical analog to digital converter with no upper limit for the input optical intensity when generating “11” codes at the output

Light angular momentum is used to characterize the dynamical rotation of electromagnetic wave, as spin angular momentum describes its polarization rotation while orbital angular momentum describes its phase rotation. Though various methods have been proposed to detect light spin or orbital angular momentum independently, it is still a challenge to determine both of them simultaneously. Here, based

Magnetic resonance (MR) images spatial resolution, which is a key factor in early diagnosis of many diseases, is fundamentally limited by the signal-to-noise ratio, which in turn depends upon the efficiency of the receive radiofrequency coils design. Many various multi-channel coils were designed to improve the quality of MR images. Another way to enhance the quality of magnetic resonance imaging (MRI)

This paper introduces a novel lateral quantum well solar cell, and investigates the effects of structural parameters of these nanostructures on the device’s performance. For modeling the device, first, the absorption coefficients and the reflectance parameters of the device at different regions were calculated. Those parameters were then used to find the system’s optical generation rate. Finally, while

A novel compact photonic crystal ring resonator is designed based on phase-change material (PCM) to realize reconfigurable directional-coupler switching for the two wavelengths of coarse wavelength division multiplexing (CWDM) system at 1530 nm and 1550 nm. The working mechanism of this PCM-based device is analyzed from the perspective of the coupled optical field in the inner and outer resonator rings

We propose a new graphene-based THz circulator. It consists of a circular graphene resonator and three graphene nanoribbon waveguides of W-geometry placed on a dielectric substrate. Surface plasmon-polariton waves propagate in the waveguides. The nanoribbon excites in the resonator dipole resonance. Nonreciprocity of the device is defined by nonsymmetry of the conductivity tensor of the magnetized

A novel hybrid all-optical infrared switch based on metal-insulator-metal plasmonic and one dimensional photonic crystal structures is introduced in this paper. A photonic crystal lattice composed of two different (low and high refractive index) Kerr materials is located at the center of the switch. Two plasmonic metal-insulator-metal waveguides are used to transfer the data signal. Also, two dielectric

In this paper, the behavior of radiation including the reconfiguration capability of planar metallic antenna structure using graphene in the microwave (MW) and terahertz (THz) frequency range is investigated. Different from the conventional reconfigurable metal planar antenna and graphene plasmonic THz antenna designs, this planar microstrip metal antenna structure is realized by placing a graphene

In this study, a pyramid Ag–Fe embedded graphene oxide nanocomposite (PAFG) was synthesized and characterized using field emission scanning electron microscopy (FESEM), energy-dispersive X-ray spectroscopy (EDS), and ultraviolet–visible (UV-V–visible (UV–vis) spectroscopy. FESEM images indicated the successful synthesis of exfoliated graphene sheets with a thickness of 7 nm, 30 nm Fe nanoparticles

Photonic quasicrystals are of particular interest for waveguiding applications because of their beneficial advantages over conventional photonic crystals, such as higher-order rotational symmetry and more isotropic Brillouin zone. In this work, by use of a 12-fold symmetric photonic quasicrystal lattice and an optofluidic infiltration approach, we sought to design a hollow-core fiber for telecom C