Applied Physics B最新文献

{"title":"Correction: Simultaneous spatially resolved temperature, pressure, and velocity measurements in high‑enthalpy gas environments using spectrally resolved laser‑induced fluorescence of potassium vapor","authors":"Joshua A. Vandervort, Spencer C. Barnes, Sean Clees, Christopher L. Strand, Ronald K. Hanson","doi":"10.1007/s00340-025-08440-z","DOIUrl":"10.1007/s00340-025-08440-z","url":null,"abstract":"","PeriodicalId":474,"journal":{"name":"Applied Physics B","volume":"131 4","pages":""},"PeriodicalIF":2.0,"publicationDate":"2025-03-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143645659","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Single longitudinal mode 486.1 nm wavelength laser generation from BBO-optical parametric amplifier system for ocean detection","authors":"Qihui Luo,&nbsp;Jian Ma,&nbsp;Zizheng Huang,&nbsp;Tingting Lu,&nbsp;Junxuan Zhang,&nbsp;Haoda Ma,&nbsp;Xiaolei Zhu,&nbsp;Weibiao Chen","doi":"10.1007/s00340-025-08449-4","DOIUrl":"10.1007/s00340-025-08449-4","url":null,"abstract":"<div><p>A single longitudinal mode (SLM) 486.1 nm blue pulsed laser was investigated by adopting a single-frequency distributed feedback laser (DFB) injected optical parametric oscillator (OPO) and optical parametric amplifier (OPA) structure, pumped by a 355 nm ultraviolet SLM laser at pulse repetition rate of 200 Hz. The maximum output pulse energy of 22.0 mJ was obtained from this injection seeded OPO/OPA system, corresponding to an energy extraction efficiency of 35.4% and a peak power of 3.73 MW. The central wavelength of output laser pulse was 486.134 nm, which was well matched to the H-β Fraunhofer line of solar spectrum, and the detected spectral linewidth was around 120 MHz.</p></div>","PeriodicalId":474,"journal":{"name":"Applied Physics B","volume":"131 4","pages":""},"PeriodicalIF":2.0,"publicationDate":"2025-03-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143612201","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Privacy-preserving face recognition using a cryptographic end-to-end optoelectronic hybrid neural network","authors":"Yi Geng,&nbsp;Zaikun Zhang","doi":"10.1007/s00340-025-08442-x","DOIUrl":"10.1007/s00340-025-08442-x","url":null,"abstract":"<div><p>Privacy-preserving technology has emerged in recent years as a solution to the privacy leakage issues associated with biometric recognition. However, the task of recognizing individuals in large datasets presents formidable challenges, including high computational burden and time delays, while still ensuring privacy protection and efficiency. To tackle these challenges, we proposed a novel cryptographic end-to-end optoelectronic hybrid neural network (CE²OHNN) designed specifically for privacy-preserving face recognition. The CE²OHNN cascades a compact optical encryption (COE) system at the front-end for image encryption, and an electronic neural network (ENN) at the back-end for face recognition directly on ciphertext images. This architecture not only enables real-time inference by utilizing high-speed and parallel optical encryption instead of digital encryption, but also offers enhanced security and computational resource savings by eliminating the need for image decryption. In this work, we proposed a compact and lightweight COE system, the security of which is validated against known-plaintext attack (KPA). Through simulations with the ORL dataset, we assess the recognition accuracy of the CE²OHNN, which achieves an accuracy of 96.67%, comparable to the baseline model’s 99.17%. Furthermore, this work holds potential for extension to other applications such as recognition of de-identified attributes like age and gender.</p></div>","PeriodicalId":474,"journal":{"name":"Applied Physics B","volume":"131 4","pages":""},"PeriodicalIF":2.0,"publicationDate":"2025-03-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143602426","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Effect of longitudinal alternating magnetic field on the dynamic behaviour and joint properties of laser scanning welding of T2 red copper","authors":"Lifang Mei,&nbsp;Yu Liang,&nbsp;Dongbing Yan,&nbsp;Shanming Luo,&nbsp;Zhiheng Zeng,&nbsp;Qingying Dai","doi":"10.1007/s00340-025-08429-8","DOIUrl":"10.1007/s00340-025-08429-8","url":null,"abstract":"<div><p>To address the issues of high reflectivity and poor stability in laser welding of T2 red copper, this study aimed to combine non-contact magnetic field with laser welding, proposing an alternating magnetic field-assisted laser welding technique. Furthermore, the approach combined theoretical analysis and experimental research to establish a thermal-fluid coupling numerical model and conduct experiments to explore the effect of an alternating magnetic field on the weld quality of laser scanning welding of T2 red copper. The results indicated a high consistency between numerical simulations and experimental results regarding the weld geometry. The introduction of the alternating magnetic field increased weld pool temperature, fluid flow velocity, weld pool width and depth, and keyhole depth. It also weakened the distortion degree of the keyhole wall, decreased the oscillation amplitude of the deep penetration keyhole, and improved the stability of the weld pool. When the alternating magnetic field with a frequency of 50 Hz and a strength of 40 mT, the temperature rise rate, weld pool width, weld pool depth, keyhole depth reached their respective maximum values of 8.438 K/ms, 1.29 mm, 1.51 mm, 0.95 mm, representing significant improvements of 3.76%, 11.21%, 7.86%, 49.6% respectively, compared without an alternating magnetic field. The variance of the keyhole depth achieved its minimum value of 0.012 m², representing significant reductions of 47.83%, compared without an alternating magnetic field. Additionally, the application of the alternating magnetic field also further suppressed metal vapor plasma eruptions, improved the weld surface morphology, refined the grain structure, and enhanced the mechanical properties and electrical conductivity of the weld joint. When the alternating magnetic field with a frequency of 50 Hz and a strength of 40 mT, the microhardness, tensile strength, and electrical conductivity reached their respective maximum values of 72.2 HV, 275 MPa, and 75.96 mS/m, representing significant enhancements of 22.37%, 58.05%, and 15.56%, respectively, compared without an alternating magnetic field. The average value and standard deviation of the metal vapor/plasma area achieved their minimum values of 1045.2 pixels and 336.23 pixels, representing significant reductions of 31.98% and 15.38%, respectively, compared without an alternating magnetic field. The introduction of the alternating magnetic field can effectively enhance the coupling efficiency of laser energy during the laser welding process of T2 red copper, optimize the weld pool dynamics, and significantly improve the welding stability and joint quality. The application of the alternating magnetic field provides a new research direction for improving the process performance of laser welding of T2 red copper.</p></div>","PeriodicalId":474,"journal":{"name":"Applied Physics B","volume":"131 4","pages":""},"PeriodicalIF":2.0,"publicationDate":"2025-03-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143612318","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Quantitative analysis of interferometric interrogation technique used for πFBG sensors","authors":"Deepa Srivastava,&nbsp;Sudipta Sarkar Pal,&nbsp;Divya Dhawan,&nbsp;Bhargab Das","doi":"10.1007/s00340-025-08438-7","DOIUrl":"10.1007/s00340-025-08438-7","url":null,"abstract":"<div><p>In this study, we conduct a quantitative analysis of the interferometric-based phase-sensitive interrogation principle for πFBG sensors using numerical simulations. The path imbalance of the interferometer arms and the line-shape function of the light signal from the πFBG sensor are critical factors influencing the sensitivity and dynamic range characteristics of the interferometric interrogation principle. Our analysis reveals several unique response characteristics that will be valuable for designing and optimizing interferometric interrogation principle using πFBGs as sensing elements. The simulation results are validated through experimental studies on πFBG sensors with in-house fabricated fiber-based Mach–Zehnder interferometers, which have path length differences of 10 mm, 19.40 mm, 28.90 mm, and 37.10 mm, respectively.</p></div>","PeriodicalId":474,"journal":{"name":"Applied Physics B","volume":"131 4","pages":""},"PeriodicalIF":2.0,"publicationDate":"2025-03-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143612137","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Comparison of the high harmonics emission from monolayer hexagonal two-dimensional solids: borophene, graphene, gallium phosphide, and boron nitride","authors":"A. M. Koushki","doi":"10.1007/s00340-025-08436-9","DOIUrl":"10.1007/s00340-025-08436-9","url":null,"abstract":"<div><p>Based on the real-time time-dependent density functional theory (TD-DFT), we theoretically investigate the influence of bandgap on the high-order harmonic generation (HHG) from monolayer hexagonal two-dimensional (2D) solids: gallium phosphide (GaP), graphene, borophene (graphene-like), and boron nitride (h-BN) under a few-cycle linearly- and/or single circularly-polarized laser field. Our results show that the overall current is prominently larger in the zigzag (ZZ) direction in comparison with the armchair (AC) direction, when the laser field is polarized along the ZZ-direction. Accordingly, the high-order harmonics can be produced more efficiently along the ZZ-direction than that of the AC-direction. We exhibit that single-layer 2D materials can generate bulk-like high-order harmonics when they are driven by an in-plane polarized laser field, and atomic-like harmonics when driven by an out-of-plane polarized laser field. Our findings indicate that due to the difference in the effective mass of carriers along AC- and ZZ-directions, the high-order harmonics spectra are different in both directions. In addition, the results illustrate that the dependence of HHG intensity changes according to the polarization of the laser electric field. The bandgap significantly affects the HHG, most importantly through ultrafast modification of the interband polarization of the system. Finally, based on the present study, due to the relatively higher yield of emitted harmonics from borophene and GaP, they have outstanding potential for future utilization in extreme-ultraviolet, efficient table-top HHG sources, and as an ultrafast optical tool to provide possibilities for imaging solid structures.</p></div>","PeriodicalId":474,"journal":{"name":"Applied Physics B","volume":"131 4","pages":""},"PeriodicalIF":2.0,"publicationDate":"2025-03-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143594732","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Investigation of 3D elemental distribution on the dome surface of HL-2A divertor by laser-induced breakdown spectroscopy","authors":"X. R. Huangfu,&nbsp;D. Zhao,&nbsp;D. Wu,&nbsp;J. Liu,&nbsp;Y. He,&nbsp;X. Shi,&nbsp;J. Han,&nbsp;L. Gao,&nbsp;L. Cai,&nbsp;J. Wang,&nbsp;J. Gao,&nbsp;C. Ke,&nbsp;H. Ding","doi":"10.1007/s00340-025-08435-w","DOIUrl":"10.1007/s00340-025-08435-w","url":null,"abstract":"<div><p>In this work, three-dimensional (3D) diagnostics of the graphite tile surface elements in the dome region of the HL-2A divertor in both poloidal and toroidal directions were investigated using laser-induced breakdown spectroscopy (LIBS) technology under simulated HL-2A vacuum conditions. LIBS spectroscopic analysis revealed the presence of impurity elements such as Si, Cu, Ca, Al, Fe, Cr, Ni, and Mn on the graphite tile surface. Depth profile results of the impurity deposited layer on the shoulder part of graphite tile showed that Fe, Cr, Ni, and Mn emission intensities gradually decreased and disappeared with depth. The Si, Cu, Ca, and Al initially increased, then decreased, and eventually disappeared in the depth profile. Two-dimensional (2D) depth profile results of impurity elements in the poloidal direction showed significant asymmetry in impurity deposition within 70 mm of the shoulder and 20 mm from the top, and the impurity layer thickness on the shoulder greater than that on the top (approximately 5.7 μm vs. 3.1 μm). Further 3D imaging of the surface elements of the HL-2A divertor demonstrated strong asymmetry of impurity elements on the graphite tile surface in the poloidal direction, but no significant asymmetry was observed in the toroidal direction within 50 mm.</p></div>","PeriodicalId":474,"journal":{"name":"Applied Physics B","volume":"131 4","pages":""},"PeriodicalIF":2.0,"publicationDate":"2025-03-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143581046","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"LIFSim, a modular laser-induced fluorescence code for concentration and temperature analysis of diatomic molecules","authors":"A. El Moussawi,&nbsp;S. Karaminejad,&nbsp;J. Menser,&nbsp;W. G. Bessler,&nbsp;T. Dreier,&nbsp;T. Endres,&nbsp;C. Schulz","doi":"10.1007/s00340-025-08388-0","DOIUrl":"10.1007/s00340-025-08388-0","url":null,"abstract":"<div><p>Laser-induced fluorescence (LIF) is a non-invasive optical diagnostics technique frequently used in reactive media to measure physical properties such as gas-phase species concentrations and temperature. It provides important information for understanding reaction and transport processes. For deriving detection schemes that provide selective and quantitative information, fluorescence spectra of the species of interest as well as potential interference sources must be simulated. LIFSim 4.0 is a modular software for simulating absorption, LIF excitation, and LIF emission spectra of NO, SiO, OH, and O₂ that also can be extended by the user to include other species. Line positions, line broadening, and collisional quenching are calculated based on spectroscopic data from literature. The code provides spectral analysis tools to interrogate and analyze sensitive spectral regions suitable for derivation of temperature from multi-line LIF measurements. The library includes fitting functions optimized for enhancing and accelerating the post-processing of stacked LIF images with varied excitation wavelength for temperature imaging and separation of the target LIF signal from broad-band or scattering background as well as tools for assessing the validity of results in non-ideal measurement situations.</p></div>","PeriodicalId":474,"journal":{"name":"Applied Physics B","volume":"131 4","pages":""},"PeriodicalIF":2.0,"publicationDate":"2025-03-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s00340-025-08388-0.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143581047","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Nonlinear optical properties of Azo compound synthesized via diazonation reaction using continuous wave laser beams","authors":"M. J. Ashoor,&nbsp;Sadiq M. H. Ismael,&nbsp;Hanadi M. Jarallah,&nbsp;H. A. Sultan,&nbsp;Qusay M. A. Hassan,&nbsp;Kawkab Ali Hussein,&nbsp;C. A. Emshary","doi":"10.1007/s00340-025-08428-9","DOIUrl":"10.1007/s00340-025-08428-9","url":null,"abstract":"<div><p>In the presence of nitrite and an aqueous hydrochloric acid medium, sulfadiazine is diazonated to create an azo compound. With the chemical formula (E)-4-((3- (tert-butyl)-2-hydroxy-5-methoxyphenyl) diazenyl)-N-(pyrimidin-2-yl), the compound is a synthetic benzenesulfonamide. Characterization of the azo molecule is done using mass, FTIR, and ¹H and ¹³C NMR spectra. Azo compound structure is optimized using Density Functional Theory (DFT). This study examines the nonlinear optical (NLO) characteristics of the azo compound via the utilization of two visible, continuous wave (CW) laser beams. The nonlinear refractive index (NLRI) and the nonlinear absorption coefficient (NLAC) of the azo compound are estimated using diffraction patterns (DPs) and Z-scan and found equal to 5.38 × 10^–7 cm²/W and 2.03 × 10^–3 cm/W, respectively. The DPs are numerically simulated using the Fraunhofer approximation of the Fresnel-Kirchhoff integral with good accord compared to the experiment’s findings. The all-optical switching (AOS) behavior of the azo compound is examined under irradiation with 473 and 532 nm CW laser beams.</p></div>","PeriodicalId":474,"journal":{"name":"Applied Physics B","volume":"131 4","pages":""},"PeriodicalIF":2.0,"publicationDate":"2025-03-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143581311","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Narrow linewidth apodized coupling grating distributed feedback lasers enabled by enhanced uniformity of photon density distribution","authors":"Dengfeng Luo,&nbsp;Nan Zhang,&nbsp;Lei Wang,&nbsp;Kai Wang","doi":"10.1007/s00340-025-08434-x","DOIUrl":"10.1007/s00340-025-08434-x","url":null,"abstract":"<div><p>Apodized coupling gratings distributed feedback (AC-DFB) lasers have demonstrated their ability to achieve narrow linewidth. However, the detailed impacts of facet coatings and the structural parameters of apodized coupling gratings on the longitudinal spatial hole burning (LSHB) effect, along with comprehensive evaluations of how the LSHB influences linewidth and in-depth optimizations in AC-DFB lasers, have yet to be thoroughly investigated. In this study, we present the physical models for AC-DFB lasers and utilize numerical simulations to investigate the influences of facet coatings and the structural parameters of apodized grating on the LSHB effect. The promoted uniformity of photon density distribution of AC-DFB lasers is achieved through the rational design of the apodized grating coupling coefficient distribution and length, which effectively modulates the optical field of the lasers. The further thorough analysis of AC-DFB laser linewidth, considering the impact of the LSHB effect, demonstrates that optimization can reduce linewidth broadening caused by the LSHB by 80.9%, narrowing the linewidth to 43.4 kHz at 120 mA with HR-AR facet coating. This study provides valuable insights into the precise optimization of AC-DFB laser, contributing to improved narrow linewidth performance and supporting their application in high-speed optical communication systems.</p></div>","PeriodicalId":474,"journal":{"name":"Applied Physics B","volume":"131 3","pages":""},"PeriodicalIF":2.0,"publicationDate":"2025-03-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143571179","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}