Optical and Quantum Electronics最新文献

Janus 2D materials attract significant scientific interest because of their unique physical properties. This article uses first-principles calculations to present a novel class of Janus monolayers XMoYH (X = S, Se, Te; Y = N, P, As) and systematically explore their electronic, spintronic, and optoelectronic potential. Cohesive energy and phonon calculations confirm the stability of all nine possible XMoYH monolayers. SMoNH is the most stable, with the lowest cohesive energy of − 8.18 eV. All studied monolayers exhibit semiconducting behavior, with PBE bandgaps of 1.02–1.92 eV and HSE-calculated gaps of 1.37–2.36 eV. A pronounced electrostatic potential asymmetry (Δϕ = 0.71–2.77 eV) is observed across the thickness of the Janus monolayers. Janus XMoYH monolayers exhibit Zeeman and Rashba spin splittings near K/Γ points due to Mo’s d-orbital spin-orbit coupling and asymmetric structure, making them promising for valleytronics and spintronics. XMoYH monolayers also exhibit strong absorption capabilities, with coefficients reaching up to 3 × 10⁵ cm⁻¹ in the visible range and as high as 7 × 10⁵ cm⁻¹ in the near-ultraviolet region. Driven by strong light absorption, the potential of XMoYH monolayers as p–i–n photodetector channels is investigated. SMoNH, SeMoNH, and SeMoAsH show peak photocurrent densities of 40.5, 22.2, and 14.4 A/m² for near-UV detection, while TeMoAsH, with 7.1 A/m², is promising for infrared detection. In addition, the XMoYH p–i–n photodetectors exhibit peak photoresponsivity (R_ph) between 0.23 and 0.64 A/W, underscoring the significant promise of the proposed monolayers for use in photodetection devices.

In this paper, we propose a simple 2D-colloidal photonic crystal (CPhC) based biosensor to detect cancer infected cells (Jurkat, HeLa, PC12, MDA-MB-231, MCF-7, White matter, Low grade glioma and Glioblastoma) in human body. The structure of the proposed biosensor consists of 13 × 13 array of titania (TiO₂) nanospheres embedded in an air matrix featured by a nanocavity within the lattice. The incorporation of nanocavity in the CPhC template results in a sharp confinement of electric field, makes it effective for detecting diseased cells. Detection is based on the resonance peak shifts when the cancer cells are introduced into the nanocavity. The reflection spectrum and electric field distribution of the biosensor are investigated by performing numerical electromagnetic simulations based on finite element method (FEM). We calculated the sensitivity ((:S)) and quality factor ((:Q)) of the proposed biosensor for CPhC templates with both hexagonal and square lattice arrangements. A performance comparison with previously reported cancer sensors for Jurkat cancer cells reveals that our hexagonally arranged biosensor achieves an optimal balance between (:Q) and (:S), with maximum values reaching (:0.97times:{10}^{5}) and 318.000 nm/RIU, respectively. Moreover, our biosensor design utilizes the self-assembly of colloidal particles, offering a time-efficient and cost effective fabrication process. Hence, eliminates the need for expensive lithographic techniques commonly employed in many previous biosensor models.

This paper demonstrates a tunable and switchable multi-wavelength Erbium-doped fiber laser (EDFL) utilizing a cascaded architecture of nonlinear polarization rotation (NPR) and Sagnac loop filter. By adjusting intracavity polarization controllers (PCs), the fiber laser achieves switchable output from 1 to 11 distinct wavelengths with a tuning range exceeding 29.6 nm. Critically, the wavelength spacing between output channels can be dynamically modulated. The laser exhibits a high optical signal-to-noise ratio (OSNR) of 25.62 dB. This highly flexible EDFL design, offering dynamic control over the output wavelength count and range, coupled with a reconfigurable wavelength spacing that is set by the length of the PMF within the Sagnac filter, is well-suited for wavelength division multiplexing systems and fiber optic sensing applications requiring adaptable multi-wavelength sources.

We perform a computational investigation of an optimized InGaN solar cell structure featuring a p-In₀.₅₃Ga₀.₄₇N / p-In₀.₇₀Ga₀.₃₀N / n-In₀.₇₀Ga₀.₃₀N (p-p-n) configuration using SCAPS-1D simulation software. This design integrates a dual-bandgap grading approach to simultaneously enhance carrier collection and suppress recombination. Compared to the conventional p-n structure, the p-p-n architecture achieves a power conversion efficiency (PCE) of 31.05%, with J_sc = 38.58 mA/cm², V_oc = 0.9207 V, and a fill factor of 87.41%. External quantum efficiency (EQE) reaches nearly 100% in the 300–820 nm range and maintains 91.4% at 1000 nm due to reduced infrared absorption. These results, obtained under ideal assumptions (defect-free layers, perfect interfaces, and no polarization fields), represent an upper-bound of achievable performance. This study proposes an optimized p-p-n InGaN design with dual bandgap grading, demonstrating improved efficiency compared to conventional p-n structures, achieving an 18.7% relative efficiency improvement.

This study presents the fabrication of α-Al₂O₃-based nanocomposites reinforced with amorphous Si₃N₄ nanoparticles through a carefully engineered processing route. The slurry preparation involved Dolapix CE64 as a dispersant, magnetized water, and ultrasonic wave vibration (UWV), followed by a shear force–thin-layer drying stage to achieve uniform nanoparticle dispersion. Consolidation was carried out via Spark Plasma Sintering (SPS) at 1550 °C under 100 MPa for 10 min. An L25 Taguchi design was applied to optimize the processing parameters and minimize experimental variability. The optimized composition—Sample 25 (0.1 wt% amorphous Si₃N₄ + 2 wt% Dolapix CE64, magnetized water, UWV, and shear force–thin-layer processing)—achieved a remarkable improvement in densification and mechanical reliability. Compared with monolithic α-Al₂O₃, the optimized nanocomposite exhibited a substantial increase in relative density (92.9% → 99.6%) and Weibull modulus (5.22 → 14.2), indicating enhanced structural integrity and uniformity. Microstructural analyses (FE-SEM, EDS mapping, and XRD) confirmed homogeneous dispersion of Si₃N₄ and refined grain morphology, directly correlating with the observed mechanical response. Importantly, the optimized sample demonstrated greater deformation tolerance prior to fracture, reflecting a pronounced reduction in brittleness while maintaining competitive strength. These results reveal that the synergistic use of amorphous Si₃N₄ nanoparticles, magnetized water, and ultrasonic-assisted dispersion in the SPS process can yield dense, tough, and damage-tolerant alumina nanocomposites, offering new opportunities for advanced structural and wear-resistant applications.

The development of lead-free double perovskite materials with superior optoelectronic properties, stable structures, and environmental friendliness is an important focus in physics, chemistry, and materials science. In this study, we report the synthesis of the double perovskites Rb₂B′BiCl₆ (B′ = K, Li) and investigate their optical and structural characteristics. Both Rb₂KBiCl₆ and Rb₂LiBiCl₆ exhibit strong ultraviolet light absorption and indirect band gaps in the wide-band-gap range, suggesting potential for applications such as UV–LEDs and other optoelectronic devices. The prepared compound Rb₂KBiCl₆ crystallise in the cubic Fm3̅m space group, with subtle B-site cation effects on the crystal framework. The as-synthesised double perovskite exhibited exceptionally stable chromaticity when continuously exposed to 365 nm UV light, with (x, y) coordinate values of 0.27 and 0.24. These results highlight Rb₂B′BiCl₆ perovskites as environmentally friendly materials with potential in stable, wide-band-gap optoelectronic applications.

Data authentication is essential for modern security systems, as it ensures the integrity and authenticity of transmitted information. This work presents a novel way to data authentication that makes use of carrier-reservoir semiconductor optical amplifiers (CR-SOAs) and Mach–Zehnder Interferometers (MZIs). Utilizing CR-SOAs' special qualities to facilitate all-optical processing and optical signal amplification. The MZIs, integrated with CR-SOAs, provide the required phase modulation and signal routing for effective data authentication. In this study, we first use the SHA3-224 algorithm to convert the secured information into a fixed-size hash value. Next, we transmit the hash value using an encryption method. Using a decryption technique, we decrypt the encrypted information that was received at the receiving end. Then, we compare the decrypted information with the information that is being converted using the SHA3-224 algorithm from the original secured information. When the two values coincide, the information is regarded as genuine. On the other hand, a difference in the values suggests that the information has been altered. The operations of the circuit are theoretically described and proven through numerical simulation using Matlab. Benefits of the system include interoperability with current optical networks, minimal power consumption, and high-speed operation. Our findings demonstrate the significant potential of CR-SOA-based MZIs as a feasible tool for improving data authentication in security systems. As a result, the reliability and privacy of data in essential communication infrastructures can be significantly improved.

A two- dimensional photonic crystal-based biosensor has been used for kidney diseases detection. The proposed structure has the dimension of silicon rods as 21*19 in air background. It has been used for the detection of glucose, albumin, urea and creatinine concentration in blood and urine samples. It senses changes in concentration/refractive index due to the blood and urine components existing in the sample. The proposed device is investigated by considering the electric field distribution spectra and photonic bandgap of the materials at a resonant wavelength by using plane wave expansion methods (PWE) and finite difference time domain methods (FDTD). The simulation results evaluate the remarkable sensitivity (2300 nm/RIU), quality factor (1562), and detection limit (0.000441) RIU for glucose, and the sensitivity (5200 nm/RIU & 3400 nm/RIU), quality factor (1559 & 1558.7), and detection limit (0.000190 & 0.000438) RIU for albumin and urea in urine sample. Also, for creatinine concentration in blood sample, sensitivity (952.4 nm/RIU), quality factor (244), and detection limit (0.00682) RIU have been achieved.

In this work, Eu³⁺/Tb³⁺ doped and co-doped NaCaPO₄ phosphors were synthesised via the solution combustion route. The X-ray diffraction (XRD), morphological, photoluminescence, energy transfer and I–V characteristics of the NaCaPO₄:Tb³⁺, Eu³⁺ phosphor were examined. The codoped samples exhibited tunable green to orange-red emissions, attributed to Tb³⁺→ Eu³⁺ energy transfer. Energy transfer parameters were calculated, and the underlying mechanisms were thoroughly discussed. In addition, I–V characteristics of blank as well as Eu³⁺ co-doped NaCaPO₄:Tb³⁺ phosphor-coated solar cells were investigated under solar simulator as well as direct sunlight. The findings portray improved performance for the coated cells. This exhaustive study recommends the synthesized phosphors promising for WLED and solar cell applications.