Optical and Quantum Electronics最新文献

In this study, we theoretically investigate the optical response characteristics of an output probe field in a hybrid double-cavity optomechanical system, which consists of a gain cavity, a charged object, along with a passive cavity that is made up of an optical parametric amplifier (OPA). There is a change from bistability to tristability when OPA and the charged parts are included. The combined impacts of OPA, gain-loss parameters, and coupling strength may be used to manipulate optical transmission rates as well as optical second-order sideband (OSS) efficiency. We further demonstrate how boosting the number of charges may significantly improve OSS efficiency. Specifically, we show that by modifying system settings, one may transition from slow to fast light or vice versa. Our findings indicate a suitable platform for improving or steering optomechanically generated transparency devices, with potential applications in optical communications, precise measurement, storage, and sensitive technology.

The beam spreading is essential for evaluating the higher-order Gaussian beam when it propagates through atmospheric turbulence. In this paper, we investigate the impact of individual atmospheric parameters such as jitter, turbulence, wind speed, and thermal blooming on beam spreading of Hermite Gaussian (HG), and Laguerre Gaussian (LG) beams. We also examine spot size variations due to beam quality on various HG and LG modes. It is seen that the impact of spreading caused by beam quality and turbulence is higher than that of jitter, wind speed, and thermal blooming. As the mode order increases, the effect of turbulence strength increases, leading to more spread for HG and LG beams. Spreading due to diffraction and beam quality on higher mode LG beam is higher than the HG beam in different modes. Beam spreading due to thermal blooming for the lower mode is higher compared to the higher mode for LG and HG beams. The sensitivity of higher mode LG beams to turbulence distortions is greater than HG beams as they experience more significant fractional increases in their spot size due to turbulence. The combined beam spread for the Laguerre Gaussian beam is larger than the Hermite Gaussian beam. This paper aims to understand better individual beam spreading in the atmosphere and its impact on the overall performance of higher-order laser propagation to develop optimized laser systems.

Effect of 10 MeV Electron irradiation on Dye-Sensitized Solar cell Efficiency based on KBr/PVA Solid Polymer Electrolyte (SPE) was studied using various techniques. Raman and XPS studies reveals that the irradiation affects the micro-structure/surface chemistry and is attributed to the crosslinking, chain scission, the free radical formation and carbonization induced by irradiation within the samples. The FESEM and AFM studies shows the evolution of elevated square stage like structure and results into amorphization of the SPE at a higher irradiation dose. These structural modifications are reflected in the form of enhancement of dielectric and conductivity properties of the SPE with irradiation dose. These results suggests that the irradiation creates the complexes within the sample and forms hydrogen depleted carbon network within the polymeric matrix. As a result of this modification the electrical conductivity increases with irradiation dose and the maximum conductivity of 3.42 × 10^–2 S/cm is observed for 300 kGy at 373 K temperature. The electrical measurements suggests that the modified conductivity results follows Jonscher’s power law for all the samples. Using the pristine and 300 kGy dose irradiated SPE samples the dye-sensitized solar cell (DSSC) was fabricated and the efficiency of the same was studied.

In this paper, the superiority of Ge/Ge_0.98Sn_0.02asymmetrical supper lattice structure based vertically doped nano-scale pin photo-sensor under operating wavelength of 1200 nm to 2200 nm is reported. The authors have developed non-linear Strain Modified Quantum-Corrected Drift–Diffusion (SMQCDD) model for analyzing the electrical and optical characteristics of the photo-sensor. The inclusion of a small amount of Sn (2%) into the pure Ge material creates in-plane bi-axial strain in the intrinsic region (i-region) of the device. This results in increases in the value of the out-plane mobility of the charge particles. As a result, the overall performance of the photo-sensor enhances significantly. The authors have used in-plane induced bi-axial strain to accelerate the out-plane mobility of the charge particles by incorporation of the exotic asymmetrical supper lattice structure in the i-region of the photo-sensor. The validation of the non-linear SMQCDD model is performed through comparison of the simulated data obtained from SMQCDD model with the experimental results under a-like thermal/structural/electrical conditions. Additionally, the authors have designed 3X2 array of photo-sensors and studied the photo-electrical characteristics at the said operating wavelength. The proposed device offers better performance in terms of quantum efficiency (0.619: single-type photo-sensor; 0.708: array-type photo) and photo-responsivity (0.056 A/W: single-type photo-sensor; 0.808 A/W:for array-type photo-sensor)at 1600 nm wavelength compared to its conventional flat Si counterpart. The developed exotic pin photo-sensor can be used as a sensing device for applications in optical communication and bio-medical systems. As far as the authors are aware, this is the first report on nano-scale Ge/Ge_0.98Sn_0.02exotic pin photo-sensor.

Industrial Wireless Sensor Networks (IWSN) is the cornerstone of the factories of the future. The massive volumes of heterogeneous data generated from large-scale IWSNs still pose challenges to the establishment of predictable, deterministic, and real-time transmission scheduling. One of the major obstacles in wireless sensor networks (IWSNs) is the reduction of collisions caused by adjacent nodes transmitting simultaneously over a single channel. The Optimized TDMA Framework for Optimized Channel Interference Mitigation Algorithm (OCIMA) has been developed in order to prevent transmission collisions. Specifically, the suggested TDMA approach significantly reduces the collision during the data transmission, while simultaneously minimizing the high priority packets transport latency. The nodes are first positioned throughout the experimental area at random. Using the Self-Adaptive Affinity Propagation Clustering (SAAPC) Algorithm, the deployed nodes are clustered to form clusters, with a cluster head selected. Self-adaptive affinity propagation consists of the initial phase, setup phase, and communication phase. After clustering, channel interference can be avoided using the TDMA approach combined with the Gazelle Optimization Algorithm (GOA). To prevent data collisions, each network cluster is given time slots via the TDMA mechanism. The optimal practicable performance of TDMA can be attained by choosing a sufficient amount of time slots for the complete data transfer. For that, GOA optimization is developed to choosing the optimal timeslots. According to the simulation analysis, the OCIMA technique that was created which have 12.4 J residual energy, 94% packet delivery ratio, and 986 s network lifetime. Thus, the proposed approach is the better choice for avoiding the mitigation of TDMA during data transmission.

The influence of the nonlinear response of the interface on the localized state formation near at the boundary between medium with Kerr nonlinearity an exponential graded-index medium is analyzed. The linear and nonlinear responses of the interface are taken into account. The cases of self-focusing and defocusing nonlinearities of the Kerr medium are considered. Exact analytical solutions describing the asymmetrical spatial profiles of localized states and analytical solutions to dispersion equation in different cases are found. The intensity at the interface reduces in the case a defocusing nonlinear response of the interface and it enlarges in the case a self-focusing nonlinear response of the interface with an increase in the localization energy. The spatial distribution of localized states with two asymmetrical maxima can arise with a relatively small value of the characteristic width of an exponential graded-index medium corresponding to the ground state characterized by no more than one maximum in the graded-index medium. The appearance of the second maximum is possible in the case of contact only between a self-focusing medium and the graded-index medium and is due solely to the presence of a nonlinear response of the interface. The localized states with the spatial profiles attenuating with oscillations in the graded-index medium are found with a significant increase in the characteristic width of a graded-index medium.