Optical and Quantum Electronics最新文献

A new series of sodium borosilicate glasses doped with different concentrations of Y₂O₃, with the composition of 58B₂O₃–12SiO₂–((30{-}x))Na₂O–(x) Y₂O₃, with x = 0, 1, 2, 4, and 8 mol%, were prepared by melt-quenching methods. The amorphous status was confirmed by XRD analysis. The molar volume ((V_{m}) cm³/mol) of these glasses decreased from 27.01 to 24.25, while the density (ρ g/cm³) increased from 2.45 to 3.27 g/cm³. The FTIR technique examined the structure of the fabricated glasses. The role of yttria in the glass is investigated. As a result, the concentration of (BOs) increases with the rising content of Y₂O₃ in the BSNY glass matrix. This increase in BO₄ enhances the overall structural integrity of the glass. The optical properties of the glass system were systematically investigated. A decrease in the energy gap was observed with increasing yttria concentration in the fabricated composition, while the refractive index exhibited a corresponding increase. The optical band gap values ranged from 3.56 to 2.91 eV, and the refractive index varied between 2.25 and 2.44, respectively. Additional factors and coefficients, including optical conductivity, electronegativity, metallization, reflection loss, steepness parameter, and transmission factor, were accurately evaluated. The fabricated glass system demonstrates significant potential as a promising material for advanced optical and electronic applications.

In this research, we presented a four-level atomic model to investigate the impact of rotary photon drag on temporal cloaking, taking into account the influence of Kerr nonlinearity with stepwise increases in Kerr field intensity. The temporal cloaking intervals we recorded were (5 mu s, 9.6 mu s, 15.6 mu s, 22.8 mu s,) and (31.4 mu s). Additionally, our findings indicate that while the temporal gap remains consistent during the light beam's transmission along the mechanical axis of rotation under the effect of rotary photon drag, the pulse intensity experiences distortion with increasing dragging angle. The numerical outcomes suggest promising applications in fields such as image design, image encoding, photonic crystal discovery, optical sensing technology, and secure communication with reduced noise between transmission and reception channels.

This study explores the potential of Antimony Selenide (Sb₂Se₃) as an absorber layer (AL) for solar cells (SCs), focusing on its optical and electronic properties for enhancing photovoltaic performance. Using SCAPS-1D simulation and density functional theory (DFT), the material’s indirect bandgap of 1.12 eV was confirmed, with photon absorption beginning above 1 eV. The reflectivity of Sb₂Se₃ is significant in the 2.5–12 eV range, and its energy loss function is minimal in the visible spectrum, which is critical for achieving high-efficiency solar cells. Additionally, the optical conductivity peaks between 2 and 12 eV, with a maximum extinction coefficient at 2 and 9 eV, further highlighting its suitability for solar applications. The study optimizes device parameters, including defect density (Nt), absorber layer thickness, acceptor (N_A) and donor (N_D) densities, and series (Rs) and shunt (Rsh) resistances. The impact of environmental factors such as working temperature (WT) and sunlight intensity on device performance was also systematically investigated to understand the efficiency of Sb₂Se₃ solar cells under real-world conditions. Copper thiocyanate (CuSCN) and tin sulphate (SnS₂) were identified as the optimal electron transfer layer (ETL) and hole transfer layer (HTL), respectively. After these optimizations, the device demonstrated a remarkable power conversion efficiency (PCE) of 28.38%, with a short-circuit current density (Jsc) of 40.32 mA/cm², an open-circuit voltage (Voc) of 0.8207 V, and a fill factor (FF) of 85.78%. These results underscore the promising potential of Sb₂Se₃ as a high-efficiency absorber material for solar cells, with significant implications for future photovoltaic device development and material optimization strategies.

A multi-band, graphene-based anisotropic metamaterial absorber designed to operate in the terahertz (THz) range features two circular split ring resonator arrays, each with two gaps and a connecting rod. This metamaterial is simulated using the frequency domain in CST Software. In addition, equivalent circuit models (ECMs) were derived to provide alternative approach to assess the characteristics of transverse electric (TE) and transverse magnetic (TM) modes using MATLAB code. The absorber is dynamically tunable, exhibiting a strong linear dichroism (LD) response of 98% within the 0.5–5.75 THz range. It achieves a single absorption peak with a 99.9% rate in TM mode and three absorption bands with an average rate of 97.1% in TE mode. This absorber has potential applications in THz polarization-sensitive devices and systems.

This study examines a novel design for hollow core metal fibers HCMF by systematically altering geometric factors. Various materials, such as gold, silver, aluminum, graphene, and silicon nitride Si₃N₄, were examined as substitutes for conventional metallic components to assess their influence on fiber performance at a wavelength of 9.5 µm. The optical losses of each material were studied using Lumerical Ansys 2023 and the finite-difference time-domain approach. Results demonstrated that Si₃N₄ had outstanding optical characteristics, with negligible optical loss approaching zero at the specified wavelength, rendering it suitable for low-attenuation applications; regarding the selection of Si₃N₄ as the material for the metal wires in the hollow-core fiber, subsequent modifications to the geometry, such as wire widths and the spacing between the wires and the core, enhanced fiber performance, achieving an optical confinement loss as minimal as 10⁻¹⁸ dB/m. This illustrates Si₃N₄ capability as an exceptional material for highly efficient hollow-core fiber configurations.

We analyze the propagation characteristics of a General Model vortex Higher-order cosh-Gaussian beam (GMvHchGB) in a turbulent oceanic medium. The beam’s intensity expression is derived using the Huygens–Fresnel integral formula. Through numerical simulations, the average intensity distribution is evaluated, focusing on the effects of oceanic turbulence and the incident beam parameters. The results indicate that the received intensity depends on the initial parameters and the oceanic conditions. Notably, under stronger oceanic turbulence, the GMvHchGB a transformation, losing its initial structure and quickly evolving into a Gaussian profile. This transformation is influenced by a reduction in the dissipation rate of turbulent kinetic energy per unit mass or an increase in the dissipation rate of mean-square temperature and the ratio of temperature to salinity fluctuation. Additionally, the initial beam parameters significantly affect the GMvHchGB’s intensity in the oceanic turbulent medium. These findings offer insights into potential applications in underwater optical communication between ships, divers, and submarines, as well as imaging systems.

New types of nonlinear interface waves propagating along a planar interface between a hyperbolic gradient medium and nonlinear medium characterized by a step-wise change in the Kerr nonlinearity coefficients under the electric field influence are obtained. The influence of the waveguide system parameters on the spatial profiles of the field distribution in the direction transverse to the interface is analyzed in detail. The height of the peak intensity of waves in the case of self-focusing nonlinearity increases, and that of waves in the case of defocusing nonlinearity decreases with an increase in the effective refractive index. The maximum intensity of the wave field in a self-focusing medium can be located in the nonlinear near-interface layer, and the peak can move to the hyperbolic gradient medium with an increase in the characteristic distance of the hyperbolic profile, however, the maximum intensity of the wave field in a defocusing medium can always be located in the hyperbolic gradient medium. The influence of the waveguide system parameters on the control of the width of the formed near-interface layer for the waves of the two types under consideration differs significantly. Comparative analysis of the relative intensities and relative power flows shows that their behavior is identical depending on the control parameters of the waveguide system at a qualitative level. The largest share of energy flow is concentrated in the nonlinear near-interface layer in the case of self-focusing nonlinearity and it is concentrated in the hyperbolic gradient medium in the case of defocusing nonlinearity.

This study presents a comprehensive computational investigation of multi-layered graphene-phosphorene structures for tunable absorption in the mid-infrared region (25–60 THz). Using Finite-Difference Time-Domain simulations, we explore the unique properties of asymmetric dark mode configurations in these structures. Our work introduces several novel aspects, including a systematic comparison of graphene and phosphorene as dark mode materials, revealing their distinct absorption characteristics and stability. We also introduce mixed-material structures, combining graphene and phosphorene dark modes to achieve tailored absorption profiles. Furthermore, we analyze dynamic tunability through Fermi level adjustment in graphene layers, demonstrating the potential for adaptive sensing applications. A detailed study on the impact of sample layer positioning on sensing performance provides crucial insights for optimizing refractive index sensors. We observe that structures incorporating diverse dark mode materials exhibit enhanced absorption peaks at higher frequencies. The asymmetric configuration allows for complex mode interactions, leading to the formation of multiple Fabry–Perot cavities and resultant absorption peaks. Our findings show that mixed-material structures can achieve sensitivities up to 14.13 THz/RIU with a figure of merit of 33.885 1/RIU, surpassing many existing designs. This work provides a foundation for designing advanced, tunable plasmonic sensors in the mid-infrared range, with potential applications in sensing.

The influence of BaTiO₃ on the structural, thermal, mechanical, and radiation shielding characteristics of borate glass with the composition of (60-x)B2O₃ + 10SrO + 15Na₂O + 15CaO + (x)BaTiO₃ (where x: 0, 2.5, 5, 7.5, and 10 mol%) was manufactured using the conventional melt quenching technique. The physical, thermal, mechanical, and radiation shielding capabilities of the glasses manufactured with this specified composition were systematically examined. As the BaTiO₃ concentration increased from 0 to 10%, the density of the glass climbed by 11.85%, and the thermal stability of the glass (ΔT) improved with the increasing BaTiO₃ concentration. The microhardness measurements of the obtained glasses ranged from 5.35 to 5.84 GP. The MAC value at 81 keV is 0.0939 cm⁻¹ for 0% BaTiO₃ and increases linearly with BaTiO₃ concentration, reaching 0.1288 cm⁻¹ for 10% BaTiO₃. The Mass Attenuation Coefficient (MAC) values for five distinct gamma energies were simulated using the MCNP6.2 software, using the Monte Carlo approach, and then compared with experimental data. The trustworthiness of our results was corroborated by comparison with theoretical data from XCOM, demonstrating strong concordance across the experimental, theoretical, and simulated findings.