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Ultrathin and broadband metamaterial absorber with loaded four lumped resistors is proposed and analyzed. The reported design is based on increasing the absorptivity by reducing the reflection and transmission coefficients simultaneously. Therefore, continuous metallic ground is used to achieve zero transmission while the reflection is reduced by matching the impedance of the proposed metamaterial absorber with the impedance of free space (Z = Z0 or μr = εr). Additionally, electric and magnetic resonances are achieved simultaneously with perfect absorptivity. The finite element method is used to simulate and analyze the reported absorber. The suggested absorber shows higher absorption than 90% over large frequency range (14.35–29.18 GHz) for both transverse electric and transverse magnetic polarizations. Further, the proposed design has high absorption through incident angle variation from 0° to 50°. Therefore, the reported perfect metamaterial absorber has good potential applications in communications, stealth and imaging fields.

Reduction of the crosstalk (CT) between contiguous photonic components is still a big challenge in fabricating high packing density photonic integrated circuits (PICs). Few techniques to accomplish that goal have been offered in recent years but all in the near-IR region. In this paper, we report a design for realizing a highly efficient CT reduction in the MIR regime, for the first time to the best of our knowledge. The reported structure is based on the silicon-on-calcium-fluoride (SOCF) platform with uniform Ge/Si strip arrays. Using Ge strips shows better CT reduction and longer coupling length (Lc) than the conventional Si based devices over a wide bandwidth in the MIR region. The effect of adding a different number of Ge and Si strips with different dimensions between two adjacent Si waveguides on the Lc and hence on the CT is analyzed using both full vectorial finite element method and 3D finite difference time domain method. An increase in the Lc by 4 orders of magnitude and 6.5 times are obtained using Ge and Si strips, respectively, compared to strips-free Si waveguides. Consequently, crosstalk suppression of − 35 dB and − 10 dB for the Ge and Si strips, respectively, is shown. The proposed structure is beneficial for high packing density nanophotonic devices in the MIR regime, such as switches, modulators, splitters, and wavelength division (de)multiplexers, which are important for MIR communication integrated circuits, spectrometers, and sensors.

An ultra-compact hybrid plasmonic grating based transverse electric (TE) pass polarizer using SOI platform is proposed and analyzed. The reported structure utilizes bi-metallic grating of noble metals; rhodium (Rh) and silver (Ag) as plasmonic materials to get benefit from their attractive properties. The rhodium is a corrosion-free, nonoxidizing, and chemically inert against aggressive chemicals noble metal. In conjunction with the use of Ag, Rh ensures better plasmonic response. The bi-metallic combination Ag/Rh exhibits large coupling between the quasi transverse magnetic mode confined in the silicon core and the surface plasmon mode constructed at the dielectric/metal interface, while the TE-mode can propagate with minimal losses. The modal characteristics of the proposed device are numerically investigated using full vectorial finite difference method, while the propagation analysis is performed using finite difference time domain method via Lumerical software package. The numerical results show that the TE-pass polarizer of a compact device length (LD) = 3.5 μm offers an extinction ratio (ER) of 36.6 dB and an insertion loss (IL) of about 0.8 dB at λ = 1.55 μm. Additionally, the reported polarizer is robust to fabrication errors keeping the ER larger than 20 dB and the IL less than 1 dB despite changing the geometrical parameters by $$\pm \hspace{0.17em}$$ ± 10% in the wavelength range of 1.4 to 1.7 μm.

In this paper, a novel design of photonic crystal fiber (PCF) biosensor based on surface plasmon resonance (SPR) is introduced and analyzed for cancer cell detection. The full vectorial finite element method (FVFEM) is used throughout the numerical analysis of the suggested biosensor. The reported PCF has a V-shaped surface that is coated with ZrN as a plasmonic material. A coupling occurs between the core guided mode and surface plasmon mode SPM which depends on the studied analyte. Such a coupling is improved by using the suggested V-shape geometry which increases the sensor sensitivity.The geometrical parameters are optimized to achieve high sensor sensitivity. The proposed biosensor has high optical sensitivity of 6214.28, 3800, and 5008.33 nm/RIU, for quasi-transverse magnetic (TM), and 6000 nm/RIU, 4400 nm/RIU, and 5333.3 nm/RIU, for quasi-transverse magnetic (TE), for breast, basal, and cervical cancer cells, respectively. The reported optical sensor can pave the way for efficient and simple technique for cancer detection with low cost and high sensitivity instead of surgical and chemical techniques.

Highly sensitive D-shaped plasmonic photonic crystal fiber (PCF) sensor is proposed, analyzed and fabricated for refractive index (RI) sensing. The reported sensor relies on the coupling between the core guided mode and the surface plasmon mode at the metallic/dielectric interface. The resonance frequency is a function of the analyte RI within a range of 1.33–1.354. Therefore, the reported D-shaped PCF holds great potential as a highly sensitive RI sensor to detect an unknown analyte refractive index within the tested RI range. The geometrical parameters are studied to maximize the sensor sensitivity by using full vectorial finite element method. Then, the optimum design is fabricated by using stack and draw technique. The fabricated PCF sensor achieves high sensitivity of 294.11 nm/RIU with a resolution of $$3.4 \times 10^{ - 4} \;{\text{RIU}}$$ 3.4 × 10 - 4 RIU . The reported RI sensor can be used for glucose concentration detection where the analyte refractive index changes with the glucose concentration within the studied RI range. Hence, this design will play a significant role in the biomedical sensor industry.

In this work, highly sensitive D-shaped photonic crystal fiber (PCF) sensor with plasmonic pyramid grating is introduced and analyzed. The sensing mechanism depends on the coupling between the fundamental core mode and the surface plasmon mode around the plasmonic pyramid grating. The resonance frequency depends on the analyte refractive index (RI) which can be employed to detect the analyte RI changes. The geometrical parameters of the proposed PCF and gold pyramid grating are studied to enhance the RI sensor sensitivity. The simulation results are obtained using full vectorial finite element method. The suggested sensor has higher sensitivity of 5200 nm/RIU than 3340 nm/RIU of the conventional grating design through the studied RI range from 1.355 to 1.385. Therefore, the reported RI sensor can be used for basal cancer cell detection with normal and cancerous cells’ refractive indices of 1.36 and 1.38, respectively. Additionally, linear performance is achieved using the reported design.

Detection of partial discharge (PD) is vital to reassure the operation reliability of high voltage (HV) electrical power systems. Optical detection methods have been developed in recent years due to their high sensitivity and immunity to electromagnetic interference. In this work, D-shaped photonic crystal fiber sensor based on surface plasmon resonance is reported for optical PD detection in HV equipment. A photochromic spirooxazine dye-doped silica sol–gel is utilized for sensing the UV radiation emitted from the PD. The sol–gel refractive index depends on the radiation intensity which affects the resonance wavelength where coupling occurs between the core and surface plasmon modes. The sensing performance is demonstrated with the help of full vectorial finite element method (FVFEM). The geometrical parameters are studied to maximize the sensor sensitivity where high sensitivity of 2.4 nm/mW.cm−2 is achieved. To the best of our knowledge, it is the first time to use a simple design of plasmonic PCF for optical PD detection.

In this paper, a new design of hybrid plasmonic photonic crystal (PhC) waveguide is proposed and analyzed at operating wavelength of 1550 nm. The suggested design consists of hybrid cylindrical core with periodic grating as a cladding region. The effective index (neff), propagation length (Lp), and normalized mode effective area (Aeff) of the supported modes are numerically investigated using full vectorial finite element method. The cladding geometry is tuned to obtain long propagation length with good field confinement. The reported plasmonic PhC with uniform grating achieves long propagation length and low propagation loss of 124 µm, and 0.035 dB/µm respectively. Further, the PhC with chirped cladding offers propagation length and low propagation loss of 162 µm, and 0.0268 dB/µm at λ = 1550 nm, respectively.

In this paper, we present a novel extension of the well-known split-step Fourier transform (SSFT) approach for solving the one-dimensional nonlinear Schrödinger equation (NLSE), which incorporates the fiber loss term. While this essential equation governs the pulse propagation in a lossy optical fiber, it is not supported by an exact analytical solution. In this regard, extended versions of the Fourier pseudospectral method (FPSM) and Hopscotch method (HSM) are effectively established as well to cope with the fiber losses effects associated with the pulses’ propagation through the fiber optics, and thus, numerous comparisons are exhaustively conducted among these three compelling numerical approaches to validate their reliability, stability, and accuracy. Based on this, the MATLAB numerical findings bolster that the extended version of the SSFT approach demonstrates superior performance over the other suggested schemes in simulating the solitons propagation in a lossy optical fiber.

Recently, photonic crystal fibers (PCFs) have become of significant interest due to their various applications, especially in the mid-infrared (mid-IR) regime. In this work, an optical mid-IR modulator based on silicon D-shaped PCF (Si-D-PCF) with vanadium dioxide (

In this paper, we studied the electrochemical capacitive performance of thermally evaporated copper iodide thin film doped with different quantities of Al (3, 5, 7, and 9 mol%). The morphological structure, crystalline nature, and surface composition of the deposited films with different dopant levels were confirmed using X-ray powder diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and field-emission scanning electron microscopy (FE-SEM). The electrochemical performance was evaluated based on cyclic voltammetry (CV), galvanostatic charge-discharge (GCD) measurements, and electrochemical impedance spectroscopy (EIS) in a Na

In this paper, four compelling numerical approaches, namely, the split-step Fourier transform (SSFT), Fourier pseudospectral method (FPSM), Crank-Nicolson method (CNM), and Hopscotch method (HSM), are exhaustively presented for solving the 1D nonlinear Schrodinger equation (NLSE). The significance of this equation is referred to its notable contribution in modeling wave propagation in a plethora of crucial real-life applications such as the fiber optics field. Although exact solutions can be obtained to solve this equation, these solutions are extremely insufficient because of their limitations to only a unique structure under some limited initial conditions. Therefore, seeking high-performance numerical techniques to manipulate this well-known equation is our fundamental purpose in this study. In this regard, extensive comparisons of the proposed numerical approaches, against the exact solution, are conducted to investigate the benefits of each of them along with their drawbacks, targeting a broad range of temporal and spatial values. Based on the obtained numerical simulations via MATLAB, we extrapolated that the SSFT invariably exhibits the topmost robust potentiality for solving this equation. However, the other suggested schemes are substantiated to be consistently accurate, but they might generate higher errors or even consume more processing time under certain conditions.

Nowadays, the development of modern optical systems relies on optical device size minimization and operating power reduction. Optical modulator based on silicon on insulator (SOI) platform is a key element in different optical systems. Therefore, the optical modulator with compact size and low insertion loss could improve the optical system efficiency. In this work, a novel compact optical modulator based on hybrid plasmonic/silicon layers is introduced. The full vectorial finite element method (FV-FEM) is used to numerically analyze the proposed design. Vanadium dioxide (VO

A novel design of polarization-independent surface plasmon multiplexer- demultiplexer (MUX/DEMUX) based on dual-core photonic crystal fiber with a central gold wire is proposed and analyzed. The cladding air holes are infiltrated with a nematic liquid crystal of type E7 with rotation angle φ, and the background material is a soft glass of type SF57 (lead silica). The simulation results are obtained using full-vectorial finite-difference method and coupled mode theory. At φ = 900, the suggested MUX/DEMUX has a short device length of 953.254 μm for x-polarized modes with broad bandwidths of 235 and 175 nm around wavelengths of 1.3 and 1.55 μm, respectively, with low cross-talk better than -20 dB. For y-polarized modes, the reported MUX/DEMUX has short device length of 1322.86 μm with broad bandwidths of 193 and 170 nm around 1.3 and 1.55 μm, respectively. Moreover, the polarization independence is achieved with short device lengths of 1138.06 and 1180 μm at φ = 90° and 0°, respectively.

The physical/chemical properties of carbon nanotube (CNT) have attracted much interest for applications in different fields, from microelectronic to photonic technology, due to their exiting conductivity properties, high hardness and high resistance to thermal stress. The technology to produce CNT with the desired properties is still under development. In this work, we report on fabrication CNT deposited by simple chemical route via the reaction between ferrocene and ammonium chloride in air at low temperature. UV–VIS absorption spectroscopy and Transmission Electron Microscopy (TEM) provide the experimental confirmation that CNT-like structures are present then our intention to get nanocomposites consist of CNTs and a poly methyl methacrylate by melt mixing process with high mechanical properties for principal concepts of the preparation of such materials for different applications.

Laser shock peening (LSP) is a surface treatment process for increasing the strength and reliability of metal components. Traditionally applied to aircraft parts, the technology also shows great potential for automotive and medical applications. The present study investigates the effect of multiple laser peening with and without coating on the hardness of aluminum alloy. The Vickers micro-hardness test is used to study the hardness of the alloy in different layer of the sample with different wavelengths and laser intensity. It has been initially found that metal hardness can be significantly increased with the increase of laser intensity and also with the increase of number of laser shots irradiated per unit area.