Optical and Quantum Electronics最新文献

In this paper, the stochastic-fractional Chen-Lee-Liu equation is analyzed with respect to optical fibres using conformable derivatives. An extensive bifurcation analysis is carried out to understand the many states and transitions of the system. The sensitivity analysis question examines the effect of changes in other parameters on the behaviour of the system itself. The paper presents a novel solution to the complex stochastic-fractional Chen-Lee-Liu equation by applying the improved modified Sardar sub-equation method. The results show that both the modelling and analysis of optical fibre systems affected by stochastic-fractional dynamics made significant progress. Applications of the system are explored in the fields of optical communication and signal processing. Furthermore, the paper includes detailed two-dimensional (2D) and three-dimensional (3D) graphs to illustrate the results visually and authenticate the theoretical results.

Harnessing the full solar spectrum demands absorbers that remain efficient across vast bandwidths while tolerating polarization and angle variations under realistic conditions. We report a nickel-polyimide-nickel metal-dielectric-metal metasurface engineered to trap and dissipate light through multiple coupled resonances delivering an ultra-wideband optical response within a fabrication-compatible geometry. The device sustains absorption above 90% from 152.66 to 2331.17 THz (129–1965 nm) with an average of 96.88% and remains above 80% from 107.41 THz to over 3000 THz. Under AM 1.5 illumination, it achieves a solar absorption efficiency of 96.61%. Thermal emission follows quasi-blackbody behavior, increasing from 75% at 500 K to 95.01% at 3500 K. Evaluated under concentrated solar input, the design shows strong solar-to-electrical conversion exceeding 67% at 1000 K. The design is polarization-insensitive and angularly stable, maintaining > 80% absorption up to 60° incidence. By uniting ultra-broadband absorption, near-blackbody emission and high conversion efficiency in a single, manufacturable platform, this work outlines a practical route to next-generation solar-thermal and thermophotovoltaic energy harvesting.

Many designed sensors these days identify only one specific virus creating practical healthcare limitation in real-world, as it will be more effective to detect multiple viruses for faster and more comprehensive diagnosis. This research work focused on to develop a rapid, label-free, highly accurate and cost-effective sensor device for multiple virus detection, for rapid diagnosis and improved patient care. This work presents a metamaterial based sensor for the detection of various viruses. The novel design composed of two identical semi-circle resonators on the top and polyimide as a dielectric layer in the middle. The simulations results illustrate three resonance peaks with absorption rates greater than 95% in detection frequency range from 0.6 to 3 THz. Moreover, the proposed design has been investigated for sensing performance by altering the refractive index of surrounding medium. The suggested sensor displays high Q factor, high sensitivity and Figure of merit with maximum values are 284.3, 0.86 THz/ RIU and 107.5 RIU⁻¹ in the investigating range of 1 to 1.5. This enhanced sensitivity allows the sensor to effectively detect multiple viruses including malaria, dengue, influenza A, immune deficiency syndrome (AIDS) and corona. Our findings demonstrate that this sensor holds great potential for diverse sensing applications, making it as a highly promising candidate for next-generation biosensing.

This study introduces a theoretically optimised Bloch surface wave (BSW) based sensing platform designed to detect Aflatoxin B1 mycotoxins. The platform utilises a binary one-dimensional photonic crystal composed of alternating Ta₂O₅ and SiO₂ layers, with a carefully selected Ta₂O₅ termination layer to enhance BSW excitation and its associated resonance features. The system’s optical response is modelled numerically using rigorous coupled-wave analysis of TM-polarised reflectance within a prism-coupled Kretschmann setup. The analysis reveals sharp reflectance dips under TM-polarized illumination, indicating BSW excitation when detecting aflatoxin B1 in aqueous solutions. The proposed sensor achieves a maximum sensitivity of 2.600 nm/(ng/mL), a detection accuracy of 0.7246, a quality factor of 582.09, and a figure of merit of 1.978/(ng/mL), demonstrating its potential for label-free, real-time biosensing in chemical and biomedical fields.

A photonic crystal nanocavity-based optical biosensor is proposed in this work, targeted to the detection of cancer cells and the measurement of urine/tear glucose concentration. The shift in cavity resonance, owing to the change in refractive index of the surrounding analyte, governs the sensing mechanism. Different design parameters of the biosensor are optimized for performance enhancement, leading to a quality factor of (3.6496times 10^5), sensitivity of 1158 nm/RIU, figure-of-merit of (3.46times ,10^5,text{RIU}^{-1}), and a detection limit of (2.89052times ,10^{-7}) RIU. The resonance shift (1562–1620 nm) is found to be almost linear over a wide range of RI (1.335–1.41). Simulations under exposure to different types of cancerous/ healthy cells and tear/urine samples of different glucose concentrations show the biosensor’s potential to easily detect/measure its analyte using low-cost characterization tools. An investigation of its performance robustness against fabrication imperfections shows significant imperfection tolerance of up to 20 nm, indicating high device-yield and close conformity of the results with practical ones. These merits make the sensor ideal for label-free diagnostics of biomolecules and non-invasive measurement of glucose concentration using a small footprint device.

An ensemble of circular geometric modes with several earlier unobserved ones as well as Laguerre-Gaussian petal modes of different orders are obtained in a 580 nm Rhodamine 6 G dye laser pumped by pulses of 532 nm radiation via a cuvette with an axicon in a liquid or in air. The geometric modes family is illustrated by the fractal frequency spectrum of a plano-spherical resonator. Switching of geometric to Laguerre-Gaussian modes is demonstrated in a degenerate configuration of the laser resonator simply by changing the liquid in the cuvette.

In this work, we report the synthesis and comparative evaluation of cetyltrimethylammonium bromide (CTAB)- and dodecylbenzenesulfonic acid (DBSA)-functionalized zinc oxide nanomaterials (ZOC and ZOD, respectively) as photoanodes in quasi-solid-state dye-sensitised solar cells (QS-DSSCs). The influence of surfactant-mediated surface engineering on structural, morphological, optical, and interfacial charge transport properties was comprehensively investigated. X-ray diffraction confirmed the hexagonal wurtzite phase of ZnO, with ZOD exhibiting reduced crystallinity due to DBSA-induced lattice strain. FESEM and HRTEM analyses revealed well-dispersed, spherical ZOC particles, while ZOD displayed severe aggregation attributed to π–π stacking interactions from the DBSA’s phenyl moiety. UV–vis DRS and Tauc analysis revealed a slight bandgap narrowing in ZOC (3.19 eV) compared to ZOD (3.21 eV), indicating enhanced light absorption through surfactant modulation. Photovoltaic studies demonstrated that the ZOC-based DSSC outperformed its ZOD counterpart, achieving a power conversion efficiency (PCE) of 4.78% due to enhanced photocurrent (16.73 mA cm⁻²), better charge transport (lower Rs and Rct), and prolonged electron lifetime (8.33 ms). In contrast, the ZOD-based device suffered from interfacial recombination and suppressed electron injection, resulting in a PCE of only 0.44%. These findings highlight the crucial role of surfactant selection in shaping ZnO surface characteristics and interfacial behaviour, providing a viable approach for the rational design of high-performance photoanodes in next-generation DSSCs.

Modern quantum communication systems depend heavily on large-scale array antennas, which are essential for the effective transmission and reception of quantum signals. This study offers a new array antenna design that operates in the 24–40 GHz frequency range and is specifically designed for multiband quantum-enabled 5G applications. With 192 components, the structure combines a fractal antenna geometry with a hybrid feeding mechanism. 1.6 mm in height and 50 mm × 50 mm in size, the antenna is built on a Rogers substrate. At resonant frequencies of 26.22, 30.57, 34.38, and 39.95 GHz, it exhibits enhanced gain values of 12.75, 12.39, 11.59, and 9.98 dBi, respectively, and supports multiband beamforming. Its primary advantages lie in the efficient design methodology, compact geometry, high gain, and wide bandwidth performance across multiple NR bands. The hybrid feeding mechanism and fractal configuration enable enhanced beam control and multiband functionality without increasing structural complexity.

In particular directions, the designed antenna arrays show radiated power with directivities of 11.4, 10.3, 8.87, and 9.57 dB. The antennas exhibit improved radiation characteristics at resonance frequencies in the 24–40 GHz range for angular orientations of Φ = 0°, Φ = 90°, and θ = 90°, respectively. They are compatible with 5G NR frequency bands and facilitate terrestrial V2X communication. Moreover, at resonance frequencies of 26.22, 30.57, 34.38, and 39.95 GHz, the bandwidths attained for pertinent 5G NR applications are 1.3, 1.97, 2.34, and 3.32 GHz, with corresponding peak return losses of 30.36, 22.06, 35.66, and 25.99 dB. CST Studio was used to model and validate the antenna arrays, and an RF absorber setup, power sensor, spectrum analyzer, and Vector Network Analyzer (VNA) were used for experimental validation.

Since there is a significant risk to human health from atmospheric pollutants, the impacts of NO, CO, and HCN gases’ adsorption and TM (Sc to Zn) doping on the electrical and optical characteristics of the zigzag-edged triangle graphene flakes have been examined by applying DFT computations at B3LYP-D3/6-311 + G(d). The findings generally indicate that these gases exhibit a negative adsorption energy, suggesting a strong molecular-cluster interaction. In general, CO, NO, and HCN seem to be more effectively adsorbed by the 5-TGF cluster than the 3-TGF and 4-TGF. Investigations using natural bond orbitals (NBOs). Research on the quantum theory of atoms in molecules (QTAIM) and noncovalent interaction (NCI) shows that this interaction was both strong and noncovalent. The n-TGFs (n = 3–5) flakes serve as potential adsorbents for removing CO, NO, and HCN polluting gases. They can be utilized as the fundamental structural part in the creation of gas sensors with great sensitivity.

The inorganic perovskite Ba₃SbI₃ has recently attracted attention as a promising photovoltaic absorber due to its strong optical absorption, favorable electrical conductivity, structural stability, and compositional tunability. In this work, the photovoltaic potential of Ba₃SbI₃ is systematically investigated using the SCAPS-1D simulator. Twelve perovskite solar cell (PSC) architectures were designed by integrating seven novel charge transport layer (CTL) materials to identify the most efficient configuration. The absorption coefficient and bandgap of Ba₃SbI₃, obtained from theoretical calculations and reported literature, were used as key input parameters for device modeling. Each architecture exhibited distinct optimized parameters and performance, influenced by electric field distribution, band offsets, and interface alignments. To further enhance the power conversion efficiency (PCE), the thicknesses of both the absorber and CTLs were optimized, alongside improvements from a back-reflection layer and tailored electrode work functions. The optimal device structure, FTO/n-Si/ Ba₃SbI₃/CuI/Pt achieved a maximum PCE of 26.38%, with a short-circuit current density of 44.16 mA cm⁻², an open-circuit voltage of 0.71 V, and a fill factor of 84%. This superior performance results from efficient charge extraction and reduced recombination losses enabled by optimized CTLs. These findings underscore the critical role of CTL engineering and structural optimization in advancing Ba₃SbI₃-based PSCs and provide practical guidance for their experimental realization.