查看更多>>摘要：To achieve super-resolution, a radially polarized Bessel Gaussian and a Hollow Gaussian Beam with high NA are focused. For both Bessel Gaussian and Hollow Gaussian Beams with high numerical aperture NA, the radially polarized component with two equal-intensity peaks covers 25% of the total intensity, while the longitudinally polarized component covers the rest. By focusing radially polarized Bessel and Hollow Gaussian beams, it is possible to generate various focal spots with different dimensions that are applicable for various applications in optical trapping, data storage, biomedical imaging, laser cutting, material processing, and microscopy. The effects of various Bessel beam characteristics are investigated. It was found that the beam radius reaches a minimum at a specified starting beam radius for all propagation distances and that the optimum starting beam radius is also large at long propagation distances. This findings are of great significance in optical trapping, data storage, biomedical imaging, and laser cutting.
查看更多>>摘要：In this paper, stationary optical solitons to nonlinear Schrodinger's equation having nonlinear chromatic dispersion and Kudryashov's quintuple power law nonlinearity are researched by the help of the extended version of G '/G-expansion approach, which is one of the effective integration algorithms. Linear and generalized temporal evolutions are considered. As a consequence bright, dark and singular solitons, complexiton solutions and other solutions for the governing model are recovered.
查看更多>>摘要：The random uncertainty of a projectile explosion position at the terminal trajectory makes testing difficult. To solve these problems, this paper proposes a measurement method of projectile ex-plosion position acousto-optic compound detection using acoustic sensors and compound-eye photoelectric detection sensor. A test layout mode is designed in which the compound-eye pho-toelectric detection sensor is at the center of the square test array, four acoustic sensors are at the four corners of the square test array.The compound-eye photoelectric detection sensor is used as the synchronous triggering device for the projectile explosion acoustic signal. A calculation model of the projectile explosion position is established based on the acousto-optic sensors compound detection test method. The influence of time delay uncertainty, array layout uncertainty and acoustic velocity uncertainty on the projectile explosion position are analyzed. Based on the test array platform, live ammunition tests were carried out, and the test results of the projectile ex-plosion position are consistent with the theoretical calculation and the influence law of uncer-tainty, which shows the feasibility of the proposed measurement method.
查看更多>>摘要：We study the propagation of dark solitons in the Kerr nonlinearity and parity-time (PT )-symmetric waveguides with Gaussian distribution. Fundamental characters of the dark solitons during the transportation are carefully checked in different parameter regions by the split-time-step Crank-Nicolson method. The results show that the dark solitons are bound to the center of the PT-symmetric waveguide when the central refractive index of the PT-symmetric potential is strong, and the dark soliton tends to deflect toward the gain region due to the gain/loss effect of PT-symmetric waveguide. We also find that when the dark soliton is introduced from the gain region of the PT-symmetric potential , the low-speed dark soliton is reflected by the gain region, and the high-speed dark soliton is bound to the center of the PT-symmetric potential in the corresponding parameter interval.
查看更多>>摘要：The basic component of optoelectronics technology is the optical filter, particularly the laser cut-off filter. Within this study, casting technique used to prepare polymeric composite film of (Eosin Yellow dye doped poly(vinyl alcohol) (EY/PVA)) for optical filter. This research has been per -formed on the XRD scan, UV-Vis-NIR and electrical spectroscopic analysis of EY/PVA films. XRD histogram shows reduction of composite films crystallinity. The transmittance of the films reduced as the dye content increases. A significant reduction in the composite's bandgap with Eosin Y doping is observed owing to the interactions between the functional group of the dye molecule and the hydroxide group in the PVA polymer matrix. Higher content of EY/PVA films (10 and 25) wt% can completely block incident light from 200 nm to 630 nm, which emphasizes the composite's strong potential as an effective optical filter. The optical limiting for EY/PVA films was tested with He-Ne laser beam source at the wavelength of 632.8 nm. It demonstrated the best possible optical limit behavior at high dyes content. The frequency dependence was evaluated on the AC electrical conductivity, dielectric constant, and dielectric loss were analyzed. The studied showed an improvement of the electrical conductivity and dielectric properties with increasing the EY-doping. The samples are ideal for the use of optical limits in CUT-OFF selective laser filters, solar cell, and variety of applications in industrial, electronics, pharmaceutical, medical, and related industries.applications.
查看更多>>摘要：A multifunctional metasurface using all dielectric structure comprising an array of InAs square pillar over the InSb substrate has been realized. The considered metasurface shows zero reflection and close to unity transmission at single as well as dual frequency in the terahertz spectral regime with the application of magnetic field. This metasurface also exhibits switching action from bandpass to bandstop over the designed frequency regime with the exposure of varying magnetic field from 0 to 0.2 T. The tunability in the maximum transmittance frequency is achieved by the variation in temperature of Insb substrate which acts as another control modality showing a blue shift from 2.37 THz to 2.65 THz at an average tuning rate of 0.028 THz K-1. The proposed all dielectric metasurface is designed to function as a switch, bandstop and bandpass filter for the terahertz spectral regime thus acting as multifunctional metasurface, thereby reduces inventory cost as well as additional peripheral utility devices.
查看更多>>摘要：To achieve controllable multi-point light focusing, we develop a new feedback wavefront shaping optimization algorithm called phase superposition Hadamard encoding algorithm (PS-HEA). This algorithm combines the phase superposition method with the Hadamard encoding algorithm, and uniformity coefficient H is introduced to improve the uniformity of multi-point focusing. With the PS-HEA algorithm, we experimentally realized uniform focusing and multi-point customized intensity ratio focusing of light through the scattering medium and demonstrated the strong anti noise and light control capabilities of PS-HEA in multi-point light focusing. Our research may pave the way for potential applications of optical manipulation and optogenetics.
查看更多>>摘要：Hydrates, which commonly appear in drugs, are undesirable because they may affect the stability and even efficacy of drugs to some extent. To efficiently identify the hydrates, we demonstrate a contact-less characterization method of Zinc sulfate hydrates with different water contents based on the all-fiber terahertz time-domain spectroscopy (THz-TDS). By using the continuously varying THz spectra with high resolution, the thermal dehydration process of hydrates has been accurately monitored. The THz spectra of anhydrous and different crystalline hydrates exhibit significant differences. A series of experiments on hydrate characterization confirm the unique advantages of the THz-TDS in quality control of drug.
查看更多>>摘要：Distance measurement technology can greatly aid scientific research and engineering applica-tions. The optical frequency-domain interferometry ranging method (OFDI-RM) has attracted a great deal of attention as it can achieve accuracy down to the micron and nanometer resolution. However, the main drawback of OFDI-RM is its short measuring range, which hinders its widespread use. In this paper, we present a high-performance OFDI-RM with a long distance range, high accuracy and high resolution. A high return-loss focus ranging probe is used to match the light intensity of reference and signal beams for acquiring high visibility interference fringes in the frequency domain at a distance of more than 100 mm. A novel signal processing method, which takes advantage of high-degree polynomial fitting and Hilbert transform (HT) to perfectly extract the harmonic component of the frequency-domain interference fringes, has also been demonstrated. The performance of OFDI-RM is verified by a linear motion measurement experiment. The measured range of OFDI-RM increased up to 170 mm, with an accuracy and resolution of up to 0.0040 mm-0.0005 mm/step, respectively.
Shafi, Muhammad AamirKhan, LaiqUllah, ShafiBouich, Amal...
9页
查看更多>>摘要：The production and commercialization of solar cells should meet such social criteria as price affordability, environment friendly, stability, and high efficiency of established materials.Various solar cells have been suggested and investigated in the past; but in this work, CZTS-Pemvskite tandem solar cell having a model "CZTS/PSC/CZTS/ZnO/FTO" was taken from the reported work as a reference. Furthermore, inserting the CdS as a buffer layer with the new model, "CZTS/ PSC/CZTS/CdS/ZnO/FTO" was simulated with SCAPS-1D software. Moreover, it was observed that the effect of CdS enhanced the tandem device efficiency from the base case of 22.57% without the CdS buffer layer to 25.95% with CdS and carried out further optimizations. This improvement is beneficial for CZTS-Perovskite tandem solar cells. The J-V characteristics curve and energy band diagram was generated using this model. Later on, with this new model, the effect of the thickness of CZTS layer on the solar cell's performance was investigated. So, the thickness also significantly affected the characteristic parameters of the solar cell as well as the J-V characteristics curve. Hence, a photo-conversion efficiency of 25.95% with Voc 1.18 V, Jsc 24.79 mA/cm(2) and FF 88.36%, the obtained results demonstrating that the proposed CZTS-perovskite tandem solar cell may concrete the way for the production of low-cost and more efficient photovoltaic applications.
NSTL
Elsevier