L-serinium picrate monohydrate (LSPM) is an efficient nonlinear optical material with higher SHG efficiency, molecular flexibility, less lattice strain, thermal stability, high transparency and a reasonable optical band gap. Hence, the present work focuses on the growth and characterization of the LSPM single crystal. Single crystals of LSPM were successfully grown by slow evaporation technique. The grown crystal was subjected to XRD, FTIR, Optical absorption, Photoluminescence and thermal studies to understand the structural, lattice strain, optical and thermal properties of the material, and to correlate them with the NLO response. The grown crystal is found to possess a monoclinic system with non-centrosymmetric space group P2(1). Finally, the Kurtz-Perry powder technique was carried out to confirm the SHG efficiency of the material required for device fabrication.
In this simulation study, two identical laser devices are considered as if they represent a single laser device; the intent is to overcome limitations in simulation software, OptiSystem 21. Operating parameters for these two devices are selected to be the same. The study simulated the self-mixing nonlinear effect by optical feedback via single-mode optical fiber by following the Lang-Kobayashi model. Results for observed spectroscopy related to laser dynamics during self-mixing are included for large-scale fiber lengths (5, 10, and 15 km); this is to be able to employ sensing in harsh environments. Variations in signal parameters included polarization degree and state, which in practice arise with fiber bend and twist, resulting in birefringence and subsequently different group delay. They are considered in the experiment to control chaotic dynamics. Results confirmed effectiveness for suggested signal parameter variations by giving rise to laser dynamical chaoticity specifications. Calculated Correlation Dimension is fluctuated from 2.8158 to 3.1564 which approves the chaoticity for results. Accordingly, the observed spectrum bandwidth was changed to be 10 GHz with a fiber length of 5 km and 45 degrees of polarization. The increase in chaotic signal bandwidth (BW) was reduced to 8.6 GHz at a 10 km optical fiber length and 0 degrees polarization. As for 15 km, the bandwidth reached 8.6 GHz at-90 degrees of polarization. These variations in laser spectrometry indicated more efficient sensors based on the high sensitivity property of chaotic dynamics. Such a novel sensor needs less complicated interferometry.
Free-space optical (FSO) communication is a green wireless data transmission technique that utilises light beams as a modulated carrier and is known for its high capacity. Numerous advantages of FSO technology include compatibility with unlicensed frequency bands, reduced latency, inexpensive installation costs, and large bandwidth. Because of this, it can be used for both the first and last terminal connections. However, weather-induced attenuation, especially from rain, fog, and haze, can weaken the signal-to-noise ratio (SNR) and restrict the performance of FSO systems. This work proposes a MIMO-FSO (Multiple-Input Multiple-Output FSO) system coupled with double-and triple-boost optical amplifiers to improve transmission quality and signal power, thereby addressing these issues. The system's performance is evaluated at three standard wavelengths - 850 nm, 1310 nm, and 1550 nm-using non-return-to-zero (NRZ) modulation. Experimental results show that a 32 & times;32 MIMO configuration with a triple-stage amplifier at 1550 nm achieves a maximum transmission distance of 114.8 km under clear weather conditions. The system maintains operable ranges of 14.84 km in rain, 10.48 km in fog, and 8.32 km in haze in unfavourable environments. The system's dependability across various atmospheric conditions is confirmed by thorough evaluations of the Q-factor, bit-error rate (BER), and eye diagrams.
This work introduces an integrated single-mode fiber, free space and visible light communication links in next-generation passive optical network (PON) enabled orthogonal frequency division multiplexing as well as optical code division multiplexing. The results reveal reliable fiber, FSO and VLC range of 100 km, 2800 m and 20 m, respectively, at an aggregate data rate of 2Tbpsunder critical climate and turbulence. Also, it offers acceptable power penalties of 1-2 dB with maximum power budgets of-26 dBm and-39 dBm receiver sensitivity with 12 dB insertion loss. The comparative literature underscores its advantage over other designs in terms of code implementation and overall design.
Radar systems rely on effective sidelobe suppression to concentrate energy on the primary lobe, ensuring accurate target detection and minimizing false identifications. In both military and civilian applications, sidelobe reduction plays a crucial role in enhancing precision by mitigating clutter and environmental interference. Uncontrolled sidelobe allow unwanted reflections from structures, water surfaces, and terrain, introducing noise that degrades radar sensitivity. To address this, polyphase codes are optimized using a hybrid optimization algorithm that integrates particle swarm optimization (PSO) and the gray wolf optimizer (GWO). MATLAB was utilized in the simulative analysis and optimization process. This approach combines the global search efficiency of PSO with the local refinement capabilities of GWO, achieving superior sidelobe suppression while preserving resolution and detection accuracy. The proposed method enhances radar performance by reducing interference, improving target discrimination, and increasing resilience against jamming, making it a robust solution for modern radar applications. Optimization of P4 polyphase code using genetic algorithm yields a maximum signal-to-noise ratio of 21.91dB for Tukey window. On the other hand when the P4 polyphase codes are optimized using PSO and gray wolf algorithm then for Tukey window, signal-to-noise ratio of 31.78dB is achieved. Our results shows that hybrid algorithm performs better than the other algorithms in terms of signal quality.
A multi-channel wavelength conversion system operating at frequencies of 192.8 THz and 192.34 THz with a data rate of 120 Gbps is proposed using an electro-absorption modulator (EAM). The system achieves high-quality wavelength conversion with quality factors of 20.25 dB and 21.30 dB, respectively. A mathematical framework is developed to determine the sinusoidal signal generator frequency and maximum data signal bandwidth, ensuring minimal interference between wavelength-converted signals. The study demonstrates the potential of EAM for efficient, low-power, polarization-independent wavelength conversion in optical communication systems.
This study investigates the influence of polishing lengths on the sensitivity of the D-shaped fiber (DSF)-based refractive index sensor. The DSF was prepared using the polishing wheel technique, utilizing polishing bits with diameters of 1, 2, 3, and 4 mm. The DSF sensors were coated with zinc oxide-polyvinyl alcohol, which acts as a light-matter interaction enhancer for refractive index detection. The probe detects isopropyl alcohol with a concentration ranging from 0 to 100%. The result shows the sensor's sensitivity reached a maximum of 0.1942 nm/RIU and a resolution of 2.05 & times;10(-2) RIU within the refractive index range of 1.33-1.38, demonstrating the effectiveness of the DSF probe. All DSF-coated with ZnO probes have a high linearity of above 95%. In contrast, the uncoated DSF exhibits a lower linearity (80%), indicating that ZnO is an excellent coating material for RI sensing. Additionally, the analysis reveals a direct correlation between the polishing length and the sensor's performance, underscoring the potential for optimizing the polishing process to improve sensitivity. The findings suggest that DSF sensors are promising candidates for high-precision refractive index detection in various applications.
LED light performance is significantly affected by driver performance. This article investigates how different driver topologies and controllers affect the lumen depreciation and energy efficiency of LED lamps. Brightness control, power consumption and long-term dependability under various working situations are all taken into account for investigations. With the help of AI controlled drivers efficiency is optimized and the degradation rate of luminous is minimized. Both simulation and hardware results verify that the SCGANN governed Bridgeless Buck-Boost topology enhances efficiency considerably and increase LED light lifespan. Also, these investigations showcase the potential of AI driven driver which results in smart power management system for LED lighting systems.
Nanostructured cadmium sulfide doped by copper (CdS:Cu) thin films were deposited on glass and wafer silicon by chemical bath deposition method. The prepared thin films were annealed at 250 oC at different times (30, 60, and 90 min). The structural properties of the samples were characterized using X-ray diffraction (XRD), and the crystalline size of the CdS:Cu thin films was calculated from XRD data. All samples had a polycrystalline structure, and annealing time increased the crystalline size. Field emission scanning electron microscopy of the morphology of the CdS:Cu thin films revealed the presence of nanoparticles with grain sizes ranging from 71.52 nm to 26.55 nm after 90 min of annealing. Moreover, CdS:Cu thin films were deposited on an n-type silicon substrate to prepare a CdS:Cu/Si junction, and the effects of annealing time on the electrical properties of this junction were investigated. The current density-voltage (J-V) characteristics were studied, and the results revealed that the CdS:Cu/Si junction had an ideality factor (n*) of 1.381 and a saturation current (Js) of 0.007 mA/cm(2), which increases with increasing annealing time. However, the potential barrier (Phi b) and the rectification factor (R-f) decreased with increasing annealing time, indicating a trade-off between conductivity and R(f )due to substantial changes in the electrical transmission mechanisms.
Microplastics are recognized as emerging contaminants in aquatic ecosystems, with potential impact on water quality. However, their seasonal dynamics in urban and peri-urban rivers remain insufficiently documented. In this context, the present study investigates the occurrence and seasonal variability of microplastics in surface waters, contributing to a better understanding of their distribution and temporal evolution in river systems. The results highlight the vulnerability of urban rivers to anthropogenic pressures and confirm the role of wastewater treatment plants as potential sources of microplastic contamination, emphasizing the need for effective monitoring strategies and control measures to reduce this type of pollution.
In many medicinal, environmental, and industrial applications, temperature measurement is a crucial parameter that needs to be monitored. A temperature-sensing E-shaped photonic crystal fiber is designed, with the core initially filled with air and compared the outcome with the core filled with propanol. With an emphasis on their structure, sensing processes and performance characteristics, this research investigates the integration of PCF for sensing temperature. The proposed Eshaped PCF is simulated using finite element method (FEM) in R-soft software. For both air-filled core and propanol filled core, different parameters such as birefringence, temperature, and temperature sensitivity are calculated at different wavelength ranging from 1 & micro;m to 1.7 & micro;m. The sensitivity of the designed structure ranges from -1.439 nm/& ring;C to -1.192 nm/& ring;C after filling propanol in the wavelength 1 & micro;m to 1.7 & micro;m range. And for air filled PCF the sensitivity of the designed structure ranges from -1.491 nm/& ring;C to -1.281 nm/& ring;C in the same wavelength from 1 & micro;m to 1.7 & micro;m range. The higher value of Birefringence is 7.62 & times;10(-2) which is calculated after filling propanol and that of for air filled air hole is 6.61 & times;10(-2). The main aim of the designed PCF is to focus on their potential as next-generation sensors that can overcome the drawbacks of conventional temperature sensor while providing greater functionality and versatility.
The development of all-inorganic antimony (Sb)-based perovskite-inspired solar cells (PISCs) has garnered significant interest owing to their superior stability and non-toxic nature. Nevertheless, the fabrication of high-quality all-inorganic Sb-based perovskite-inspired thin films remains a significant obstacle. Herein, all-inorganic Cs3Sb2I9-xClx thin films were synthesized by adjusting the annealing time in ambient air. As the annealing time increases from 6 to 10 min, the number of holes in Cs3Sb2I9-xClx thin film reduces. Simultaneously, its defect density decreases. However, with a further extension of the annealing time to 14 min, the number of holes for Cs3Sb2I9-xClx thin film increases and its defect density improves. Consequently, the Cs3Sb2I9-xClx thin film with annealing 10 min exhibits the best growth quality.
This work investigates the effect on the optical millimeter (mm)-wave long-haul RoF with pre-distortion systems and Fiber Bragg grating (FBG) techniques. Dual-Drive Mach-Zehnder Modulator (DDMZM) is used to generate the long-distance but inexpensive RoF mm-wave-based system by varying transmission rates of 1, 5, and 10 Gbps and power parameters of 0, 5, 10, and 15 dBm, respectively. Graphical analysis is done for Q-factor, Bit Error Rate (BER), and eye height with a 140 Km fiber link at a 10 Gbps bit rate. The results demonstrate that the system achieves excellent performance with a high Qfactor, low BER, and well-opened eye diagrams, confirming its feasibility for high-capacity and long-distance wireless access networks. Furthermore, the combination of pre-distortion and FBG techniques provides a scalable, low-cost, and energy-efficient solution, making the design highly suitable for next generation.
An EOD suit is designed to shield personnel from the effects of explosions, such as those caused by improvised explosive devices. Beside ballistic protection, it must ensure thermal comfort of the operator. Here we demonstrate the efficiency of a subvestimentar cooling system based on 1-teradecanol as phase change material macro-encapsulated in aluminized polypropylene. DSC studies prove the thermal stability of the system during 10 heating/cooling cycles, maintaining the temperature in the range 23.83 oC-45.77 oC with a mean enthalpy of transformation 224.78-229.27 J/g and mean thermal conductivity measured with the planar hot disk method 0.30165 W/mK.
This paper presents the design and performance evaluation of a mode division multiplexing (MDM)-based underwater optical wireless communication (UOWC) system employing Hermite-Gaussian (HG) modes and four-level pulse amplitude modulation (PAM-4) signaling. The system utilizes four orthogonal HG modes (HG00, HG10, HG01, and HG11) to achieve an aggregated transmission capacity of 80 Gbps (20 Gbps per mode). The optical link performance is analyzed over five distinct Jerlov water types-JI, JIA, JIB, JII, and JIII-considering the impact of increasing propagation distance on bit error rate (BER), error vector magnitude (EVM), and eye diagram characteristics. The simulation results indicate that the proposed HG-MDM-UOWC system supports reliable transmission distances of approximately 65 m, 51 m, 28.5 m, 13.2 m, and 4.75 m for JI, JIA, JIB, JII, and JIII water types respectively, at the forward error correction (FEC) threshold. Among the evaluated scenarios, JI water demonstrates the best performance with minimal EVM degradation and clear eye openings across all HG channels. The findings confirm that spatial mode multiplexing through orthogonal HG beams significantly enhances data throughput in UOWC systems, though performance strongly depends on water clarity and scattering characteristics.
In this paper, we formulate a charge-carrier mobility model for disordered organic semiconductors based on both the Arrhenius and non-Arrhenius temperature dependence. This model can correctly reproduce the effects of temperature, electric field, and carrier concentration on the carrier mobility, and can rather well fit the numerical solution of the master equation at both the low carrier density and high carrier density, the latter of which cannot be well described using the extended Gaussian disorder model (EGDM). Furthermore, experimental current-voltage characteristics in devices based on organic semiconductors are also excellently reproduced by using this mobility model. These results further suggest that a temperature dependence of mobility given by the non-Arrhenius relation is suitable for the low carrier density and small energetic disorder limitation, and the high carrier density and large energetic disorder limitation gives the Arrhenius relation.
Based on parallel Mach-Zehnder Modulators (PMZM), an optimized scheme for improving the generation of frequency quadrupling photonic millimeter-wave is proposed. In the designed scheme, by optimizing unbalanced modulation indices of each MZM, high-quality photonic millimeter-wave was still generated under non-ideal actual MZM condition. The feasibility of the proposed scheme is verified by theoretical analysis and simulation experiment. With the proposed approach, both the optical sideband suppression ratio (OSSR) and RF spurious suppression ratio (RSSR) of the generated photonic millimeter-wave have been enhanced, and the receiver sensitivity of the corresponding Radio over Fiber (RoF) transmission system has also been optimized.
Perovskite materials are emerging as leading candidates for photovoltaic applications due to their remarkable optoelectronic properties and structural tunability. This study presents a numerical simulation of a 2D perovskite solar cell using PEA(2)PbI(4 )as the absorber, modeled with SOAPS-1D. The architecture FTO/ZnO:NR/PEA(2)PbI(4)/Spiro-OMeTAD/Au was optimized by adjusting absorber thickness (750 nm), ETL/HTL thicknesses (50 nm), doping levels, defect density (10(15) cm(-3)), and resistances. The optimized device achieved a peak POE of 26.38% with excellent quantum efficiency and stability. These results highlight the importance of precise parameter tuning in enhancing 2D perovskite solar cell performance for scalable applications.
Defects in various layers of solar cells play an important role in determining the characteristics of such devices. Different types of defects such as acceptor type in Cu2O layer, donor type in TiO2 layer and neutral type on the interface (Cu2O/TiO2) have been considered to simulate the proposed solar cell with the help of SCAPS-1D software. Results obtained from this simulation show that output parameters like short circuit current density (J(SC)), open circuit voltage (V-OC), fill factor (FF) and power conversion efficiency (PCE) significantly depend on the defect density and its properties. Appropriate selection of defect density of corresponding layers may improve the device performance. Moreover, different back contact metals (Cu, Ag, Fe, Nb, Mo, Ni, Au, Pt) have been taken step by step during simulation for understanding the effects of such back contacts. It is observed that solar cell gives better results when Ni (5.22 eV) acts as back contact.
A ZnO nanowire laser (NWL) with an emission wavelength of approximately 385 nm, incorporating 0-12 pairs of distributed Bragg reflectors (DBRs), has been proposed and investigated by numerical simulation. The well-known double rate equations of the laser diode (LD) were solved numerically using the fourth-order Runge-Kutta method to analyze relaxation oscillation (RO) and photon transient response. The simulation results reveal that RO amplitude increases with increasing the number of DBR pairs, whereas the RO frequency decreases. Furthermore, the numerical results demonstrate that the turn-on delay time is significantly reduced as the DBR pair number increases, owing to the higher photon cavity lifetime.
