Abstract. Cd1 − xAgxS nanoparticles were synthesized by a simple cost-effective chemical method in air atmosphere. We have achieved novel hybrid ternary nanoparticles of high quality. The prepared samples were characterized by x-ray diffraction, Fourier transform-Raman, field emission scanning electron microscopy, transmission electron microscopy, and UV–visible absorption spectroscopy. The results

Abstract. In the framework of effective mass envelope function approximation, the impurity states in GaN / AlxGa1 − xN spherical quantum dot (QD) are calculated by plane-wave expansion method. The binding energies of the impurity in 1s and 2p± states and the transition energy between 1s state and 2p± state are calculated and analyzed in detail. Several critical influencing factors of impurity states

An approach has been suggested for the simulation of a quantum dot reflective semiconductor optical amplifier (RSOA) with wideband optical gain. This model is implemented by superimposing different quantum dot groups with various radii using solution process nanotechnology, which is both practical and frugal. Also, few works have been done, superimposing QD groups in RSOAs. A numerical method has been

Exciton–LO phonon interaction of the Fröhlich type is studied in the CdS/CdSe/CdS asymmetric double quantum well under an applied laser field. The intensity of laser effect on the exciton binding energy, oscillator strength, optical transition energies, and third-order harmonic generation are investigated by changing the right well sizes and barrier sizes. The laser-associated confined energies and

Vanadium nitride (VN)-based metamaterial absorber was investigated for ultra-wideband (UWB) nearly perfect absorber in the visible to infrared regime of the electromagnetic spectrum considering four different VN samples, namely VN6, VN8, VN10, and VN12. The absorption properties were extracted for the transverse electric and transverse magnetic incidence waves under different obliquities, and also

We present a copper indium gallium selenide (CIGS) solar cell with improved performance, numerically simulated using LUMERICAL FDTD and DEVICE Multiphysics simulation software and considering the charge transportation, ambient temperature, buffer layer thickness, and defect density for detailed analysis. One of the significant concerns of the existing CIGS solar cells is the presence of the toxic cadmium

A numerical model allows analysis of optical gain according to the electronic properties of AGaN/GaN multiple quantum well laser diode (MQWLD) under hydrostatic pressure. Finite difference techniques are used to acquire energy eigenvalues and their corresponding eigenfunctions of AGaN/GaN MQWLD. The hole eigenstates are calculated via a 6 × 6 k . p method under applied hydrostatic pressure. It was

We propose an all-dielectric metasurface with strong polarization sensitivity and large-modulation-depth for potential multiple switching applications. We show that the proposed metasurface can be efficiently tailored through symmetry breaking to support strong toroidal and trapped dipole responses across the near infrared spectrum with high Q-factors. Such two responses can be dynamically switched

The improvement of a green synthetic approach that focuses on the use of olive leaf extract took place to produce silver nanoparticles (AgNPs). This synthesis is known for its cost efficiency and ecological safety, with the potential to be applied in massive AgNP production. The cytotoxic, anticancer, and antioxidant activities of olive leaf extracts with AgNPs were examined on breast cancer cell lines

A perforated micro-ring resonator (PMRR) on the flexible SU-8 substrate is proposed and theoretically demonstrated for detecting the refractive index (RI) and the pressure simultaneously. Once a perforation defect is introduced, the symmetric and the asymmetric standing wave modes (SWMs) are formed during the mode splitting. The energy distributions of the two SWMs are quite different so that the sensitivities

The low light extraction efficiency (LEE) stemming from the transverse-magnetic dominant emission is one of the major factors limiting the performance of aluminum gallium nitride (AlGaN)-based deep ultraviolet (UV) light-emitting diodes (LEDs) when the light emission wavelengths are close to 200 nm. These wavelengths, nonetheless, are pivotal to applications including sensing and sterilization and

Avalanche photodiodes (APDs) are critical photodetection devices for high sensitivity and high-speed sensing. Great efforts in bandgap engineering and impact-ionization engineering have been put to achieve high gain-bandwidth products. Plasmonic optical antenna (POA) techniques can change the near-field distributions of the illumination light and thus provide an effective approach to achieve simultaneous

We design a dual-band absorber based on metal multiplexed gratings at mid-infrared (mid-IR) frequencies. The metal multiplexed gratings are realized with two constitutive gratings and separated from a metallic ground plate by a thick dielectric spacer in order to construct the metal–insulator–metal architecture. Simulations indicate that two different absorption frequencies from the excitation of surface

We propose an ultra-thin Huygens lens with high focusing efficiency and robustness that is composed of a unit cell with a pair of C-shaped split-ring resonators (CSRRs). Compared with the single-layer CSRR lens, the focusing efficiency of the Huygens metasurface lens improves 90% at the best focal lengths and three times at the central frequency. Our device has robustness against geometrical parameters

Amyloid-based diseases, such as amyloid light-chain amyloidosis, are characterized by misfolding of proteins and their deposition as amyloids in tissues. As prognosis is usually poor, patients suffering from these illnesses can benefit from improved detection, monitoring, and treatment techniques. The use of nanoparticles to diagnose and treat biological targets has been extensively studied, including

We report the synthesis of Ag–Au alloy nanoparticles (NPs) by post-irradiation of mixed colloidal Ag and Au NPs by a nanosecond pulse laser in the presence of an external electric field (EEF). In our study, size, optical, and plasmonic properties of colloidal Ag–Au alloy NPs were investigated. A colloid of individual Ag and Au NPs were separately prepared by nanosecond pulsed laser ablation in distilled

Using the variational method of the Pekar type, we studied the ground-state energy and the excited-state energy of a parabolic potential quantum pseudodot. Through numerical calculation and derivation, we found that (1) the ground-state energy E0 increases with the increase of V0; (2) when λ > 6, E0 and E1 are increasing functions of λ, but when λ < 5, E0 and E1 are decreasing functions of λ. In these

A surface plasmon-based hexagonal photonic crystal fiber sensor is numerically computed and studied covering a large span of analyte refractive index from 1.33 to 1.40. Structural design parameters are optimized to improve the sensor performance. Investigation of sensor sensitivity has been performed by analyzing the electromagnetic behavior of light using finite element method-based mode solver. The

An optical amplitude modulator operating at near-infrared frequencies is presented. The proposed modulator structure consists of a Fabry–Perot (FP) cavity coupled with graphene located in the middle of two dielectric Bragg mirrors. Graphene’s presence as an active material with adjustable optical conductivity, as well as its effective interaction with powerful standing waves confined in the cavity

We proposed a hybrid metamaterial structure based on graphene–silver, which has tunable, efficient light-absorbing, and light-transmitting performance at the visible light regime. It is shown that this hybrid metamaterial structure can absorb light effectively with a maximum of 97.2% at a wavelength of 638 nm and reflect light effectively with a maximum of 98.05% at a wavelength of 437 nm. In addition

A compact vertical coupler is proposed and optimized based on the multi-phase matching for three-dimensional (3D) mode (de)multiplexing [(De)MUX]. The multi-phase matching conditions can be achieved for the operating TE2, TE1, and TE0 modes of the subwavelength grating-based waveguide. The coupling strength can be significantly increased due to the subwavelength structure. The proposed 3D mode (De)MUX

We studied the electronic structure as well as the dielectric, optical, and phonon properties of PbTiO3 / CaTiO3 / SrTiO3 ferroelectric superlattices, based on the density functional theory, using the Perdew–Becke–Johnson-generalized gradient approximation exchange-correlation functional. According to the results, the superlattice under investigation possessed a semiconducting phase with an indirect

We spin coated thin films of poly(methyl) methacrylate (PMMA) polymer doped with 2-[7-(1,3-dihydro-1,3,3-trimethyl-2H-indol-2-ylidene)-1,3,5-heptatrienyl]-1,3,3-trimethyl-3H-indolium iodide (HITC) laser dye onto microscope cover slides under applied flexural stress and found the patterns of scattering (milkiness) to correlate with the spatial variation of the pressure pattern. We further deposited

We explored the design of an optical pressure sensor. The objective is to create a photonic microelectromechanical system-based cantilever sensor design to detect prostate-specific antigen, a protein biomarker associated with prostate cancer. Sensor’s performance for the early detection of cancerous cells is dependent on sensitivity. The designed sensor consists of a hexagonal ring integrated with

We report on surface-enhanced Raman scattering (SERS) activity of bimetallic core-shell Au@Ag nanorods. These nanostructures feature four plasmon maxima in the UV-visible range. Their application for SERS analysis enables matching individual optical properties of organic analytes using the optimal excitation wavelength resonant both for plasmon nanostructures and analytes. It promotes higher sensitivity

In this work, a photonic sensor based on photonic crystal fiber and surface plasmon resonance to analyze the refractive index (RI) of analytes varying from 1.440 to 1.480 is presented. A dual hexagonal lattice of air holes is reported in this proposed sensor design. The combination of titanium dioxide (TiO2) and gold (Au) is used as a plasmonic material in this sensor. The sensing capability of the

In recent years, antibody-labeled fluorescent probes have attracted wide attention in fluorescence immunochromatography. Quantum dots (QDs) are excellent fluorescent materials with some unique optical properties, including strong stability against photobleaching, broad excitation spectra, high emission intensity, good fluorescence efficiency, and narrow excitonic emission. The CdSe/ZnS QDs microbeads

A plasmonic refractive index (RI) sensor based on photonic crystal fiber is proposed. A chemically stable thin film of gold (Au) is used as an active plasmonic layer and high RI material Ta2O5 is used as an overlayer over the gold thin film. The effect of Ta2O5 thin film on the sensor performance is analyzed in detail and a novel, as per the authors’ best knowledge, operating analyte RI range tunable

We experimentally investigated simultaneous microfluidic control and visualization of a heated region using gold nanoisland/VO2 thin films. By focusing a laser on the film, we photothermally generated an air microbubble in nondegassed water. After the bubble generation, another laser spot was irradiated 48 μm away from the bubble center. As a result, a sudden onset of the rotational Marangoni flow

Plasmonic metasurfaces with in-plane phase elements have a limit in transmission because they only affect the electric field of incident EM radiation. Recently, a set of out-of-plane plasmonic phase elements was designed using a genetic algorithm to work in the infrared as a Huygens metasurface with significantly improved transmission efficiency. A beam-steering metasurface (i.e., blazed transmissive

A plasmonic structure, constituted by metal insulator metal waveguides and split annular cavity connected with rectangular resonator (SACRR), is proposed and investigated. Numerical simulation by the finite element method (FEM) has been done to investigate the transmittance properties of the proposed structure and four Fano resonances arise in the results. To analyze and verify the simulation results

The canonical boundary-value problem for Dyakonov-surface-wave propagation in a fixed direction guided by the planar interface of a uniaxial dielectric material and an isotropic nondissipative dielectric material was solved. Both partnering materials were taken to be homogeneous and the constitutive parameters for both to lie within the ranges of available materials. Solutions were found for which

We numerically analyzed the influence of geometric structures of gradient Al component AlxGa1 − xN nanowire on their light-trapping properties, ranging from nanopillars, inverted conical frustums, to inverted hexagonal frustums. COMSOL® Multiphysics package based on the finite element method is used to systematically study the effects of geometric parameters such as base radii (R), pillar height (H)

This is a list of reviewers who served the Journal of Nanophotonics in 2020.

In the current study, the linear combination operator (LCO) and Lee–Low–Pines unitary transformation (LLPUT) are adopted to verify the effect of the anisotropic parabolic potential (APP) on the polaron’s properties in the asymmetric Gaussian quantum well (AGQW). Relations of the vibrational frequency (VF) and the ground state energy (GSE) of weak coupling polaron in the AGQW for GaAs crystal varying

The enhanced Fabry–Perot (F–P) resonance caused by adding a layer of AlN film to different metal substrates (AlN/metals) was analyzed by controlling the thickness of AlN film. The obtained results using the finite-difference time-domain (FDTD) method show that the absorption capacity of visible light was changed by the film interference effect. Then, the light absorption of Au/AlN/Fe (AAF) trilayer

Abstract. We present a method to passively edge couple multiple optical fibers with silicon nitride waveguides in the visible wavelengths. We efficiently convert the fiber mode to the waveguide mode using an inverse taper mode size converter and support passive alignment using a U-groove that centers the optical fiber to the inverse taper. In our prototypes, we measure a coupling efficiency of −4.2

Abstract. The design of an ultrasensitive surface plasmon resonance (SPR) sensor for the detection of deoxyribose nucleic acid (DNA) hybridization is highly desirable for biomedical applications. We have proposed an SPR sensor architecture (Prism-SF10/Al/Si/BP/Antimonene/phosphate buffer saline solution) and performed its numerical analysis for DNA hybridization using angular interrogation at 633 nm

Abstract. An ultra-broadband perfect absorber for visible to near-infrared light utilizing a metamaterial nanostructure is theoretically proposed and numerically analyzed. The absorber consists of a square and plus shape layer of Ti-Al2O3 (top layer) and a thin layer of Cr located on a SiO2 layer over a TiN substrate. By ameliorating the dimensions of the design, an average absorption of 95.4% is attained

Abstract. A compact all-fiber temperature sensor based on a gold nanoparticle (GNP)-coated macrobent standard single-mode fiber (SMF) has been proposed and experimentally demonstrated. It can be easily constructed by just bending an SMF into a suitable bending radius to constitute a Mach–Zehnder modal interferometer. The sensing area of the bent SMF was coated with GNP utilizing the magnetron sputtering

Abstract. To reduce the effects of global warming, visible and near-infrared light must be used more efficiently. Deep ultraviolet light (8 eV) is required for the direct dissociation of CO2 by light; however, the introduction of a metal complex has made it possible to realize CO2 reduction with visible light. We demonstrate that the optical near field (ONF) can increase the CO2 reduction rate. For

Abstract. A 2D hot spot diffusion model for describing the superconducting nanowire response to a single photon is presented. Compared to the 1D hot belt model, the 2D hot spot model can capture the initial stage of the hot spot evolution after photon absorption, which is beneficial for achieving a more comprehensive understanding of the origins and underlying physics of the timing jitter in superconducting

Abstract. Nanocrystalline copper oxide (CuO) powder was synthesized through solid-state co-precipitation technique using copper sulfate pentahydrate and sodium hydroxide pellets as a source materials. Crystalline nature and surface morphology of the sample are studied through x-ray diffraction, field emission scanning electron microscopy, energy dispersive x-ray, and Fourier transform infrared spectroscopy

Nanoscale noble metal particles have great potential as optical-limiting materials, whereas the size effect of silver nanoparticles on the optical limiting has been seldom reported before now. Silver nanoparticles with different sizes are synthesized by a seed growth method, and their optical-limiting properties to nanosecond laser at 532 nm are investigated. The results showed that, under the involved

Abstract. The higher-order harmonic generation process in the nonperturbative regime at the interaction of coherent electromagnetic radiation with the AB-stacked bilayer graphene at high Fermi energies is considered. The applied coherent low-frequency radiation field in the high Fermi energy zone of electrons excludes the interband transitions enhancing high harmonic rates. The developed microscopic

Abstract. A transmission matrix method (TMM) commonly used for modeling the electromagnetic properties of multilayered biopolymer/conductive nanoparticle composites is presented, which predicts the behavior of the experimental results of the electromagnetic shielding effectiveness of a deoxyribonucleic acid-silver nanoparticle composite but falls short for accurately predicting the absolute shielding

Abstract. Tunable fluorescent silica nanoparticles (SiO2 NPs) with variable sizes based on fluorescence resonance energy transfer were synthesized. The SiO2 NPs were obtained by the Störber method by varying tetraethyl orthosilicate (TEOS) concentrations and with the incorporation of different concentrations of fluorescein (Fl) and rhodamine B (RhB) conjugated with 3-(aminopropyl)triethoxysilane. We

Nanostructured porous silicon (PS) can be used as a template for the growth of noble metal nanoparticles for the subsequent development of metal/semiconductor hybrid structures with application in several fields. The current work reports on the electrodeposition of silver nanoparticles (AgNPs) into columnar PS layers. In particular, the size, morphology, and surface density of the AgNPs grown into

Abstract. Metasurface silicon-based optical devices are highly integrated and high-performance, meeting the requirements of photonics integrated circuits. We present a design method for metasurface silicon-based gradient index (GRIN) optical lens. With easy calculation, this method supports large-area GRIN elements design. The Luneburg lens and integrated coupler are shown as examples. Such devices

Abstract. We have designed and numerically analyzed gap-enhanced toroidal dipole (TD) and magnetic Fano resonances with high Q-factors and large modulation depths simultaneously in an all-dielectric metamaterial for sensing. By introducing a gap in the cylinder, we achieved a significant enhancement in Q-factor and electromagnetic field compared to the cylinder with no gap in near-IR regime. In addition

Abstract. Zinc oxide nanoparticles (ZnO-NPs) were fabricated using carbon quantum dots (CQD) solution using a laser ablation technique to investigate the photoluminescence properties and applications for the interaction of mercury and lead ions. The ablation times were 5, 7, 10, and 13 min. The prepared samples were characterized using UV–visible spectroscopy, Fourier transform infrared spectroscopy

Abstract. Polydimethylsiloxane/multi-walled carbon nanotube (PDMS/MWCNT) composite had high photoacoustic transduction efficiency owing to its high light absorption coefficient and low interfacial thermal resistance. The high expansion coefficient and light absorption ability of PDMS/MWCNT nanocomposite films have significant positive effects when it is used as a laser ultrasonic transducer. We introduce

Schottky barrier photodetector (PD) (tungsten/nickel/aluminum nitride) based on stacked tungsten gratings is reported in our work. The absorbance of the grating-based structure is obtained using rigorous coupled-wave analysis method. In addition, a responsivity value of 6.164 mA / W is calculated at λ = 559.38 nm based on Fowler’s model. More than three times enhancement in responsivity is achieved

Abstract. Vitamin D3 acts as a crucial biomarker for various diseases. Current methods for vitamin D3 detection are time-consuming, expensive, and require trained personnel. We report a simple and cheap photodetector (PD)-based vitamin D3 detection technique for the first time using Ag nanoparticles-covered Er-doped TiO2 nanowires. The operational stability of the device was tested under the dark as

Abstract. We propose the use of metal nanoparticles (NPs) [(silver (Ag)] embedded heterogeneous composite material made of titanium dioxide (TiO2) for antireflection coating (ARC) while partially blocking the transmission of near-ultraviolet (UV) radiation across the thin-film arrangement. The proposed structure consists of two layers of porous TiO2 thin film of specific thickness and volume fraction

Abstract. Photocatalysis is a new advanced oxidation process based on the irradiation of semiconductors such as TiO2 and ZnO for photodegradation of contaminants. In this process, the semiconductor absorbs the photon energy of ultraviolet radiation, generating highly reactive species for the degradation of organic compounds. It has been reported that doping of transition metals (e.g., Cu, Ni, Co, and

Abstract. Due to the dire need to monitor, sense, and control useful and harmful chemicals for industrial, environmental, and biomedical purposes, chemical sensing has become an eminent topic among researchers. Hence, we focus mainly on a modified kagome design with a relatively high sensitivity of 99.8%, effective material loss of 0.000263 cm − 1 for constant absorption loss, and 0.0004204 cm − 1

Abstract. A compact and broadband transverse electric (TE)-pass power splitter using triple-guide directional couplers (TGDCs) is proposed and analyzed in detail, where the TGDCs are formed by two outside subwavelength grating (SWG) waveguides and a central strip waveguide with segmented hybrid plasmonic waveguides (HPWs) on its top. For input transverse magnetic (TM) mode, it is transmitted along

Abstract. A simple, low-cost, and ecofriendly method of obtaining silver nanoparticles was obtained from AgNO3 in dilution for the first time with a habanero pepper infusion. Two sets of experiments were carried out. The samples obtained in the first experiment were analyzed by SEM and TEM. Results showed that the samples prepared using 0.001 M and 0.005 M of AgNO3 and particles with an average size

Abstract. Quantum-dot cellular automata (QCA) is a potential upcoming nanotechnology for designing digital circuits with high performance. A subtractor is an important arithmetic circuit used in many digital circuits. An efficient multilayer full subtractor design is proposed using majority logic in QCA. The proposed design has only 53 cells and occupies a small area of about 0.03 μm2. Using the proposed