A mobile fiber-optic laser-induced breakdown spectrometer(FO-LIBS) prototype was developed to rapidly detect a large quantity of steel material online and quantitatively analyze the trace elements in a large-diameter ...A mobile fiber-optic laser-induced breakdown spectrometer(FO-LIBS) prototype was developed to rapidly detect a large quantity of steel material online and quantitatively analyze the trace elements in a large-diameter steel tube.Twenty-four standard samples and a polynomial fitting method were used to establish calibration curve models.The R^2 factors of the calibration curves were all above 0.99,except for Cu,indicating the elements’ strong self-absorption effect.Five special steel materials were rapidly detected in the steel mill.The average absolute errors of Mn,Cr,Ni,V,Cu,and Mo in the special steel materials were 0.039,0.440,0.033,0.057,0.003,and0.07 wt%,respectively,and their average relative errors fluctuated from 2.9% to 15.7%.The results demonstrated that the performance of this mobile FO-LIBS prototype can be compared with that of most conventional LIBS systems,but the more robust and flexible characteristics of the FO-LIBS prototype provide a feasible approach for promoting LIBS from the laboratory to the industry.展开更多
An all optical method is demonstrated for measuring the carrier-envelope phase (CEP) of few-cycle laser pulses. It is found that, in the few-cycle regime, the high harmonic spectrum generated from asymmetric molecul...An all optical method is demonstrated for measuring the carrier-envelope phase (CEP) of few-cycle laser pulses. It is found that, in the few-cycle regime, the high harmonic spectrum generated from asymmetric molecules shows several half-cycle cutoffs that change their positions as the CEP varies. Such half-cycle cutoffs represent the fingerprint of different quantum trajectories and the waveform of the driving pulse. In this case, the CEP can be accurately measured from the half-cycle cutoffs.展开更多
In recent years,a laser-induced breakdown spectrometer(LIBS)combined with machine learning has been widely developed for steel classification.However,the much redundant information of LIBS spectra increases the comput...In recent years,a laser-induced breakdown spectrometer(LIBS)combined with machine learning has been widely developed for steel classification.However,the much redundant information of LIBS spectra increases the computation complexity for classification.In this work,restricted Boltzmann machines(RBM)and principal component analysis(PCA)were used for dimension reduction of datasets,respectively.Then,a support vector machine(SVM)was adopted to process feature information.Two models(RBM-SVM and PCA-SVM)are compared in terms of performance.After optimization,the accuracy of the RBM-SVM model can achieve 100%,and the maximum dimension reduction time is 33.18 s,which is nearly half of that of the PCA model(53.19 s).These results preliminarily indicate that LIBS combined with RBM-SVM has great potential in the real-time classification of steel.展开更多
In this paper, we developed a portable laser-induced breakdown spectroscopy(LIBS) using an optical fiber to deliver laser energy and used it to quantitatively analyze minor elements in steel.The R^2 factors of calibra...In this paper, we developed a portable laser-induced breakdown spectroscopy(LIBS) using an optical fiber to deliver laser energy and used it to quantitatively analyze minor elements in steel.The R^2 factors of calibration curves of elements Mn, Ti, V, and Cr in pig iron were 0.9965,0.9983, 0.9963, and 0.991, respectively, and their root mean square errors of cross-validation were 0.0501, 0.0054, 0.0205, and 0.0245 wt%, respectively. Six test samples were used for the validation of the performance of the calibration curves established by the portable LIBS. The average relative errors of elements Mn, Ti, V, and Cr were 2.5%, 11.7%, 13.0%, and 5.6%,respectively. These results were comparable with most results reported in traditional LIBS in steel or other matrices. However, the portable LIBS is flexible, compact, and robust, providing a promising prospect in industrial application.展开更多
A dynamically tunable multiband plasmon-induced transparency(PIT) effect in a series of rectangle cavities coupled with a graphene nanoribbon waveguide system is investigated theoretically and numerically by tuning th...A dynamically tunable multiband plasmon-induced transparency(PIT) effect in a series of rectangle cavities coupled with a graphene nanoribbon waveguide system is investigated theoretically and numerically by tuning the Fermi level of the graphene rectangle cavity. A single-PIT effect is realized using two different methods: one is the direct destructive interference between bright and dark modes, and the other is the indirect coupling through a graphene nanoribbon waveguide. Moreover, dual-PIT effect is obtained by three rectangle cavities side-coupled with a graphene nanoribbon waveguide.Results show that the magnitude of the dual-PIT window can be controlled between 0.21 and 0.74, and the corresponding group index is controlled between 143.2 and 108.6. Furthermore, the triple-PIT effect is achieved by the combination of bright–dark mode coupling and the cavities side-coupled with waveguide mechanism. Thus, sharp PIT windows can be formed, a high transmission is maintained between 0.51 and 0.74, and the corresponding group index is controlled between161.4 and 115.8. Compared with previously proposed graphene-based PIT effects, the size of the introduced structure is less than 0.5 μm2. Particularly, the slow light effect is crucial in the current research. Therefore, a novel approach is introduced toward the realization of optical sensors, optical filters, and slow light and light storage devices with ultra-compact,multiband, and dynamic tunable.展开更多
An ultrafast and low-power slow light tuning mechanism based on plasmon-induced transparency(PIT)for two disk cavities aperture-coupled to a metal-dielectric-metal plasmonic waveguide system is investigated numericall...An ultrafast and low-power slow light tuning mechanism based on plasmon-induced transparency(PIT)for two disk cavities aperture-coupled to a metal-dielectric-metal plasmonic waveguide system is investigated numerically and analytically.The optical Kerr effect is enhanced by the local electromagnetic field of surface plasmon polaritons,slow light,and graphene-Ag composite material structures with a large effective Kerr nonlinear coefficient.Through the dynamic adjustment of the frequency of the disk nanocavity,the group velocity is controlled between c/53.2 and c/15.1 with the pump light intensity increased from 0.41 MW/cm^2 to 2.05 MW/cm^2.Alternatively,through the dynamic adjustment of the propagation phase of the plasmonic waveguide,the group velocity is controlled between c/2.8 and c/14.8 with the pump light intensity increased from 5.88 MW/cm^2 to 11.76 MW/cm^2.The phase shift multiplication of the PIT effect is observed.Calculation results indicate that the entire structure is ultracompact and has a footprint of less than 0.8μm^2.An ultrafast responsive time in the order of 1 ps is reached due to the ultrafast carrier relaxation dynamics of graphene.All findings are comprehensively analyzed through finite-difference time-domain simulations and with a coupling-mode equation system.The results can serve as a reference for the design and fabrication of nanoscale integration photonic devices with low power consumption and ultrafast nonlinear responses.展开更多
SrMoO_(3)(SMO)thin films are deposited on LaAlO_(3)substrates by magnetron sputtering.The effects of ambient temperature on the structural,electrical,and optical properties of the films are investigated.As the tempera...SrMoO_(3)(SMO)thin films are deposited on LaAlO_(3)substrates by magnetron sputtering.The effects of ambient temperature on the structural,electrical,and optical properties of the films are investigated.As the temperature increases from 23℃ to 800℃,the SMO film exhibits high crystallinity and low electrical resistivity,and the real part of dielectric functions becomes less negative in the visible and near-IR wavelength range,and the epsilon near zero(ENZ)wavelength increases from460 nm to 890 nm.The optical loss of the SMO film is significantly lower than that of Au,and its plasmonic performance is comparable to or even higher than TiN in the temperature range of 23℃ to 600℃.These studies are critical for the design of high-temperature SMO-based plasmonic devices.展开更多
This study introduces an innovative dual-tunable absorption film with the capability to switch between ultra-wideband and narrowband absorption.By manipulating the temperature,the film can achieve multi-band absorptio...This study introduces an innovative dual-tunable absorption film with the capability to switch between ultra-wideband and narrowband absorption.By manipulating the temperature,the film can achieve multi-band absorption within the 30-45 THz range or ultra-wideband absorption spanning 30-130 THz,with an absorption rate exceeding 0.9.Furthermore,the structural parameters of the absorption film are optimized using the particle swarm optimization(PSO)algorithm to ensure the optimal absorption response.The absorption response of the film is primarily attributed to the coupling of guided-mode resonance and local surface plasmon resonance effects.The film's symmetric structure enables polarization incoherence and allows for tuning through various means such as doping/voltage,temperature and structural parameters.In the case of a multi-band absorption response,the film exhibits good sensitivity to refractive index changes in multiple absorption modes.Additionally,the absorption spectrum of the film remains effective even at large incidence angles,making it highly promising for applications in fields such as biosensing and infrared stealth.展开更多
基金supported by National Natural Science Foundation of China(Nos.61705064,11647122)the Natural Science Foundation of Hubei Province(Nos.2018CFB773,2018CFB672)the Project of the Hubei Provincial Department of Education(No.T201617)。
文摘A mobile fiber-optic laser-induced breakdown spectrometer(FO-LIBS) prototype was developed to rapidly detect a large quantity of steel material online and quantitatively analyze the trace elements in a large-diameter steel tube.Twenty-four standard samples and a polynomial fitting method were used to establish calibration curve models.The R^2 factors of the calibration curves were all above 0.99,except for Cu,indicating the elements’ strong self-absorption effect.Five special steel materials were rapidly detected in the steel mill.The average absolute errors of Mn,Cr,Ni,V,Cu,and Mo in the special steel materials were 0.039,0.440,0.033,0.057,0.003,and0.07 wt%,respectively,and their average relative errors fluctuated from 2.9% to 15.7%.The results demonstrated that the performance of this mobile FO-LIBS prototype can be compared with that of most conventional LIBS systems,but the more robust and flexible characteristics of the FO-LIBS prototype provide a feasible approach for promoting LIBS from the laboratory to the industry.
基金supported by the Key Foundation of the Ministry of Education of China(Grant No.211117)the Foundation of Hubei Co-innovation Center forUtilization of Biomass Waste,China(Grant No.XTCX004)
文摘An all optical method is demonstrated for measuring the carrier-envelope phase (CEP) of few-cycle laser pulses. It is found that, in the few-cycle regime, the high harmonic spectrum generated from asymmetric molecules shows several half-cycle cutoffs that change their positions as the CEP varies. Such half-cycle cutoffs represent the fingerprint of different quantum trajectories and the waveform of the driving pulse. In this case, the CEP can be accurately measured from the half-cycle cutoffs.
基金supported by National Natural Science Foundation of China(No.61705064)the Natural Science Foundation of Hubei Province(No.2021CFB607)+1 种基金the Natural Science Foundation of Xiaogan City(No.XGKJ2021010003)the Project of the Hubei Provincial Department of Education(No.T201617)。
文摘In recent years,a laser-induced breakdown spectrometer(LIBS)combined with machine learning has been widely developed for steel classification.However,the much redundant information of LIBS spectra increases the computation complexity for classification.In this work,restricted Boltzmann machines(RBM)and principal component analysis(PCA)were used for dimension reduction of datasets,respectively.Then,a support vector machine(SVM)was adopted to process feature information.Two models(RBM-SVM and PCA-SVM)are compared in terms of performance.After optimization,the accuracy of the RBM-SVM model can achieve 100%,and the maximum dimension reduction time is 33.18 s,which is nearly half of that of the PCA model(53.19 s).These results preliminarily indicate that LIBS combined with RBM-SVM has great potential in the real-time classification of steel.
基金supported by National Natural Science Foundation of China (Grant Nos. 61705064 & 11647122)the Natural Science Foundation of Hubei Province (Grant Nos. 2018CFB773 & 2018CFB672)the Project of the Hubei Provincial Department of Education (Grant No. T201617)
文摘In this paper, we developed a portable laser-induced breakdown spectroscopy(LIBS) using an optical fiber to deliver laser energy and used it to quantitatively analyze minor elements in steel.The R^2 factors of calibration curves of elements Mn, Ti, V, and Cr in pig iron were 0.9965,0.9983, 0.9963, and 0.991, respectively, and their root mean square errors of cross-validation were 0.0501, 0.0054, 0.0205, and 0.0245 wt%, respectively. Six test samples were used for the validation of the performance of the calibration curves established by the portable LIBS. The average relative errors of elements Mn, Ti, V, and Cr were 2.5%, 11.7%, 13.0%, and 5.6%,respectively. These results were comparable with most results reported in traditional LIBS in steel or other matrices. However, the portable LIBS is flexible, compact, and robust, providing a promising prospect in industrial application.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.11647122 and 61705064)the Natural Science Foundation of Hubei Province,China(Grant Nos.2018CFB672 and 2021CFB607)+1 种基金the Project of the Hubei Provincial Department of Education,China(Grant Nos.B2021215 and T201617)the Natural Science Foundation of Xiaogan City,China(Grant Nos.XGKJ2021010002 and XGKJ2021010003)。
文摘A dynamically tunable multiband plasmon-induced transparency(PIT) effect in a series of rectangle cavities coupled with a graphene nanoribbon waveguide system is investigated theoretically and numerically by tuning the Fermi level of the graphene rectangle cavity. A single-PIT effect is realized using two different methods: one is the direct destructive interference between bright and dark modes, and the other is the indirect coupling through a graphene nanoribbon waveguide. Moreover, dual-PIT effect is obtained by three rectangle cavities side-coupled with a graphene nanoribbon waveguide.Results show that the magnitude of the dual-PIT window can be controlled between 0.21 and 0.74, and the corresponding group index is controlled between 143.2 and 108.6. Furthermore, the triple-PIT effect is achieved by the combination of bright–dark mode coupling and the cavities side-coupled with waveguide mechanism. Thus, sharp PIT windows can be formed, a high transmission is maintained between 0.51 and 0.74, and the corresponding group index is controlled between161.4 and 115.8. Compared with previously proposed graphene-based PIT effects, the size of the introduced structure is less than 0.5 μm2. Particularly, the slow light effect is crucial in the current research. Therefore, a novel approach is introduced toward the realization of optical sensors, optical filters, and slow light and light storage devices with ultra-compact,multiband, and dynamic tunable.
基金the National Natural Science Foundation of China(Grant Nos.11647122 and 61705064)the Natural Science Foundation of Hubei Province,China(Grant Nos.2018CFB672 and 2018CFB773).
文摘An ultrafast and low-power slow light tuning mechanism based on plasmon-induced transparency(PIT)for two disk cavities aperture-coupled to a metal-dielectric-metal plasmonic waveguide system is investigated numerically and analytically.The optical Kerr effect is enhanced by the local electromagnetic field of surface plasmon polaritons,slow light,and graphene-Ag composite material structures with a large effective Kerr nonlinear coefficient.Through the dynamic adjustment of the frequency of the disk nanocavity,the group velocity is controlled between c/53.2 and c/15.1 with the pump light intensity increased from 0.41 MW/cm^2 to 2.05 MW/cm^2.Alternatively,through the dynamic adjustment of the propagation phase of the plasmonic waveguide,the group velocity is controlled between c/2.8 and c/14.8 with the pump light intensity increased from 5.88 MW/cm^2 to 11.76 MW/cm^2.The phase shift multiplication of the PIT effect is observed.Calculation results indicate that the entire structure is ultracompact and has a footprint of less than 0.8μm^2.An ultrafast responsive time in the order of 1 ps is reached due to the ultrafast carrier relaxation dynamics of graphene.All findings are comprehensively analyzed through finite-difference time-domain simulations and with a coupling-mode equation system.The results can serve as a reference for the design and fabrication of nanoscale integration photonic devices with low power consumption and ultrafast nonlinear responses.
基金supported by the Science and Technology Research Project of Hubei Provincial Department of Education(No.D20202703)the Science and Technology Program of Guizhou Province(No.(2022)311)。
文摘SrMoO_(3)(SMO)thin films are deposited on LaAlO_(3)substrates by magnetron sputtering.The effects of ambient temperature on the structural,electrical,and optical properties of the films are investigated.As the temperature increases from 23℃ to 800℃,the SMO film exhibits high crystallinity and low electrical resistivity,and the real part of dielectric functions becomes less negative in the visible and near-IR wavelength range,and the epsilon near zero(ENZ)wavelength increases from460 nm to 890 nm.The optical loss of the SMO film is significantly lower than that of Au,and its plasmonic performance is comparable to or even higher than TiN in the temperature range of 23℃ to 600℃.These studies are critical for the design of high-temperature SMO-based plasmonic devices.
基金support by the National Natural Science Foundation of China(Nos.51606158,11604311,12074151)funding from the Sichuan Science and Technology Program(No.2021JDRC0022)+3 种基金funding from the Natural Science Foundation of Fujian Provincee(No.2021J05202)funding from the Research Project of Fashu Foundation(No.MFK23006)funding from the Open Fund of the Key Laboratory for Metallurgical Equipment and Control Technology of Ministry of Education in Wuhan University of Science and Technology,China(No.MECOF2022B01)funding by the project supported by Guangxi Key Laboratory of Precision Navigation Technology and Application,Guilin University of Electronic Technology(No.DH202321).
文摘This study introduces an innovative dual-tunable absorption film with the capability to switch between ultra-wideband and narrowband absorption.By manipulating the temperature,the film can achieve multi-band absorption within the 30-45 THz range or ultra-wideband absorption spanning 30-130 THz,with an absorption rate exceeding 0.9.Furthermore,the structural parameters of the absorption film are optimized using the particle swarm optimization(PSO)algorithm to ensure the optimal absorption response.The absorption response of the film is primarily attributed to the coupling of guided-mode resonance and local surface plasmon resonance effects.The film's symmetric structure enables polarization incoherence and allows for tuning through various means such as doping/voltage,temperature and structural parameters.In the case of a multi-band absorption response,the film exhibits good sensitivity to refractive index changes in multiple absorption modes.Additionally,the absorption spectrum of the film remains effective even at large incidence angles,making it highly promising for applications in fields such as biosensing and infrared stealth.