Optical and Quantum Electronics最新文献

Vehicle-to-everything (V2X) communication infrastructure is made possible by the latest vehicular communication technologies, which allows vehicles to convey information with any network, at any time, from any location. Vehicle networks have recently been recognized as a potential way to enhance traffic control and drivers driving experiences. Still, in existing models energy efficiency and security are essential requirements and remains challenges to modern V2X networks, including high latency, computational overhead, complexity, improper routing, and link failure. To address these concerns, the proposed method implemented an optimized DBSCAN with reinforcement learning based AODV and Homomartino Encryption for secure and energy efficient in V2X network. In the vehicular network, trusted authority has the responsibility to identify the trusted vehicles based on registered vehicles and user ID. If the event like accident happens, the V2V communication occurs between the vehicles related to the incident and cluster Head vehicle is selected using an optimized DBSCAN algorithm with Black-winged Kite Algorithm optimization to send the message to nearby RSU based on the low distance and high energy. Then the RSU validated the reliability message to determine the trusted level of the incident. Afterwards using the routing protocols as reinforcement learning based AODV to estimate the suitable route to transmit the reliable message to the base station. Homomartino encryption is used to encrypt the reliability message for secure transmission of data and uploaded it in the cloud server database, which also broadcast the alert messages to everyone in the V2X network to reduce the traffic and secure road safety management. The performance metrics obtained for the proposed model are 85.6% PDR, 12.77 J energy consumption, 26.4% routing overhead, 19.5mbps throughput, 0.73 silhouette score and also the taken for key generation, clustering, encryption, execution are 2.01, 0.30, 11.89 and 23.52 ms respectively. These results describes that the proposed energy-efficient and cryptography algorithm performs better than the other existing model and offering a more effective solution for securing V2X communication networks.

Hybrid bilayer nano-heterojunction (NiPcTs) thin films, with a p-type active donor layer and n-type silicon (Si) acceptor, were manufactured at substrate temperatures of 300 K and 400 K. Using a thermal evaporation technique under vacuum conditions of 10⁻⁵ mbar and a deposition rate of 12 nm/min, these films were deposited onto two aluminum (Al) electrodes to construct the hydride bilayer photovoltaic solar cell (PVSC). The electrical characteristics of the Al/NiPcTs/Si/Al hybrid nano-heterojunction thin layer were investigated. The findings demonstrated an open-circuit voltage (V_m) of 0.25 V, a short-circuit current density (I_m) of 2.77 mA/cm² and a fill factor (FF) of 0.391. Under illumination with a halogen lamp at an intensity of 55 mW/cm², the conversion efficiency (η) was 5.03% at a substrate temperature of 400 K. Theoretical calculations indicated that the optical energy gap of the NiPcTs thin layers depends on the annealing temperature. The optical band gap narrows as the annealing temperature rises but then widens as the temperature increases to 400 K. Comparing theoretical and experimental calculations of the electronic and electrical properties showed that the best model for solar cell applications was achieved.

By assuming low doping concentration with negligible concentration-dependent energy transfer mechanisms, we employ rate-equation formalism to derive the coupled power-gain equations in steady state and investigate the requirements of co-lasing at 2 μm and 2.3 μm in continuous-wave thulium ion (Tm³⁺)-doped lasers. We obtain an analytical condition which provides a criterion about which optical transition lases first. Analytical expressions are further derived for single-lasing and co-lasing threshold powers. By using the spectroscopic parameters for Tm³⁺:YLiF₄, our model predicts that 2.3 μm lasing can start first in gain media with low Tm³⁺ ion doping if the length of the gain medium is sufficiently long. We then discuss how the results of the low-concentration model developed in this study can be extended to the case of high doping concentration in an approximate way and obtain good agreement between model predictions and experimental co-lasing data previously obtained with Tm³⁺:YLiF₄ lasers.

The current work aims to synthesize of silicon nitride(Si₃N₄)/tin dioxide (SnO₂) nanomaterials filled poly-methyl methacrylate(PMMA) as a future and advanced nanostructures to utilize in a variety of optical and tailored nanoelectronics applications. The structural, optical and dielectric properties of PMMA/Si₃N₄/SnO₂ films were examined. The obtained results indicated that the absorbance of PMMA increased of 51.2% at λ = 280 nm (UV-S), while the transmittance reduced of 52.6% with rising Si₃N₄/SnO₂ NPs content of 6.6 wt.%. On other hand, the absorbance increased of 56.3% at λ = 580 nm (VIS-S) and 59.9% at λ = 780 nm (NIR-S). The indirect energy gap of PMMA reduced from 4.3 to 3 eV for allowed transition and from 4 to 2.3 eV for forbidden transition when the Si₃N₄/SnO₂ NPs content increased of 6.6 wt.%, and these results are important in numerous optoelectronics fields. The optical parameters of PMMA increased with increasing Si₃N₄/SnO₂ NPs content. The dielectric properties of PMMA enhanced with addition of Si₃N₄/SnO₂ NPs content. Finally, the results showed that the PMMA/Si₃N₄/SnO₂ films can be considered as potential and promising nanocomposites to exploit in various future optoelectronics nanodevices.

In this study, we explore the dynamics of coupled dispersionless equations using the Galilean transformation and planar dynamical systems theory. These nonlinear equations are pivotal in various physics and engineering domains, such as optical fibers and ferromagnetic materials. We analyze bifurcation and chaotic behavior, finding that slight variations in initial conditions minimally affect solution sensitivity, as confirmed by the Runge–Kutta method. Using the improved modified Sardar sub-equation and ((frac{mathrm {G'}}{mathrm{G}}, frac{1}{mathrm{G}}))-expansion methods, we derive exact solutions, including bright, kink, anti-kink, and dark solitons. These results demonstrate the effectiveness of the proposed methods for solving nonlinear partial differential equations.