ZEWEI LUO, GE WU, ZHI CHEN, CHINAN DANG, RONG WAN, Tao Yang, ZHENGFEI ZHUANG, AND TONGSHENG CHEN
The Structured Illumination (SI)-based Super Resolution Fluorescence Resonance Energy Transfer (SR-FRET) imaging technique, known as SISR-FRET, enables the investigation of molecular structures and functions in cellular organelles by resolving sub-diffraction FRET signals within living cells. FRET microscopy offers unique advantages for quantitatively detecting dynamic interactions and spatial distribution of biomolecules within living cells. The spatial resolution of conventional FRET microscopy is limited by the diffraction limit, and it can only capture the average behavior of these events within the resolution limits of conventional fluorescence microscopy. SISR-FRET performs sequential linear reconstruction of the three-channel SIM images followed by FRET quantitative analysis using a common localization mask-based filtering approach. This two-step process ensures the fidelity of the reconstructed SR-FRET signals while effectively removing false-positive FRET signals caused by SIM artifacts. However, the slow imaging speed resulting from the switching of excitation-emission channels in SISR-FRET imaging limits its application in fast imaging scenarios. To address this issue, this study proposes a dual-channel structured illumination super-resolution quantitative FRET imaging system and method. By incorporating a FRET dual-channel imaging and registration module into the imaging pathway, spatial switching and channel multiplexing of the SISR-FRET excitation-emission channels are achieved. Combining the image reconstruction algorithm with channel sub-pixel registration correction, the dual-channel SISR-FRET technique enhances the temporal resolution by 3.5 times while preserving the quantitative super-resolution FRET analysis. Experimental results were obtained using a multi-color SIM system to perform super-resolution imaging of living cells expressing mitochondria outer membrane FRET standard plasmids. These experiments validate the improved spatial and temporal resolution of dual-channel SISR-FRET and the fidelity of FRET quantification analysis. In summary, this research presents a novel dual-channel structured illumination super-resolution FRET imaging system and methodology. It overcomes the limitations of slow imaging speed in SISR-FRET by enabling spatial switching and channel multiplexing of excitation-emission channels. The proposed technique enhances the temporal resolution while maintaining quantitative analysis of super-resolution FRET. Experimental validation demonstrates the increased spatial and temporal resolution of dual-channel SISR-FRET and the accuracy of FRET quantification analysis. This advancement contributes to the study of molecular structures and functions in cellular organelles, providing valuable insights into the intricate mechanisms of living cells.
{"title":"Dual-channel structured illumination super-resolution quantitative FRET imaging","authors":"ZEWEI LUO, GE WU, ZHI CHEN, CHINAN DANG, RONG WAN, Tao Yang, ZHENGFEI ZHUANG, AND TONGSHENG CHEN","doi":"10.7498/aps.72.20230853","DOIUrl":"https://doi.org/10.7498/aps.72.20230853","url":null,"abstract":"The Structured Illumination (SI)-based Super Resolution Fluorescence Resonance Energy Transfer (SR-FRET) imaging technique, known as SISR-FRET, enables the investigation of molecular structures and functions in cellular organelles by resolving sub-diffraction FRET signals within living cells. FRET microscopy offers unique advantages for quantitatively detecting dynamic interactions and spatial distribution of biomolecules within living cells. The spatial resolution of conventional FRET microscopy is limited by the diffraction limit, and it can only capture the average behavior of these events within the resolution limits of conventional fluorescence microscopy. SISR-FRET performs sequential linear reconstruction of the three-channel SIM images followed by FRET quantitative analysis using a common localization mask-based filtering approach. This two-step process ensures the fidelity of the reconstructed SR-FRET signals while effectively removing false-positive FRET signals caused by SIM artifacts. However, the slow imaging speed resulting from the switching of excitation-emission channels in SISR-FRET imaging limits its application in fast imaging scenarios. To address this issue, this study proposes a dual-channel structured illumination super-resolution quantitative FRET imaging system and method. By incorporating a FRET dual-channel imaging and registration module into the imaging pathway, spatial switching and channel multiplexing of the SISR-FRET excitation-emission channels are achieved. Combining the image reconstruction algorithm with channel sub-pixel registration correction, the dual-channel SISR-FRET technique enhances the temporal resolution by 3.5 times while preserving the quantitative super-resolution FRET analysis. Experimental results were obtained using a multi-color SIM system to perform super-resolution imaging of living cells expressing mitochondria outer membrane FRET standard plasmids. These experiments validate the improved spatial and temporal resolution of dual-channel SISR-FRET and the fidelity of FRET quantification analysis. In summary, this research presents a novel dual-channel structured illumination super-resolution FRET imaging system and methodology. It overcomes the limitations of slow imaging speed in SISR-FRET by enabling spatial switching and channel multiplexing of excitation-emission channels. The proposed technique enhances the temporal resolution while maintaining quantitative analysis of super-resolution FRET. Experimental validation demonstrates the increased spatial and temporal resolution of dual-channel SISR-FRET and the accuracy of FRET quantification analysis. This advancement contributes to the study of molecular structures and functions in cellular organelles, providing valuable insights into the intricate mechanisms of living cells.","PeriodicalId":6995,"journal":{"name":"物理学报","volume":"20 1","pages":""},"PeriodicalIF":1.0,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88924264","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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}
In quantum mechanics, the Hermitian Hamiltonian is generally used to describe the ideal closed quantum system, but in reality, the physical system is closely related to the environment, and the open quantum system coupled to the environment can be described by the equivalent non-Hermitian Hamiltonian to a certain extent. Among them, the dissipation intensity is closely related to the dynamic properties of non-Hermitian quantum systems. Therefore, it is of great practical significance to study how dissipation affects particle loss. In this paper, the dynamic law related to dissipation intensity in one-dimensional non-Hermitian systems under open boundary conditions is studied, and it is found that dissipation can induce the recurrence of edge burst. After the time-dependent evolution of the particles in the one-dimensional non-Hermitian dissipative lattice system with open boundary conditions, there is an edge burst in the system, that is, there is a large probability of particle loss at the edge, and the edge burst disappears after increasing the intensity of intracellular transition. It is found that if the dissipation intensity is increased or decreased, the edge burst will reappear. This kind of reappearance is different from the original edge burst, which is mainly manifested in the loss probability distribution of particles from the edge distribution to the volume distribution, which is due to the different probability of particle motion direction in the two cases. Under the re-induced edge burst, the particles move from the initial position to the left and right directions, and the left side rebounds after reaching the boundary, forming a more obvious loss probability at the edge and gradually decreasing to the body area. In the original edge burst, the probability of particles only moving to the left is larger, and the 'trapped' is completely dissipated at the edge, forming a distribution with an independent loss peak at the edge, the movement to the left is due to due to the non-Hermitian skin effect. The deeper reason for different movement directions is related to the defect of non-Hermitian system far from parity-time symmetry breaking. Under the parameter near the parity-time symmetry breaking defect, the loss probability of the particle is unilateral distribution, and the loss probability of the particle moving to both sides is bilateral distribution when it is far away. This is the description of the dissipation-induced edge burst recurrence phenomenon and its characteristics. In addition, this paper also studies the influence of impurity barrier on the probability distribution of particle loss in non-Hermitian dynamics. The results show that placing a small barrier on the non-dissipative A-site can obviously hinder the particle motion, and when the barrier increases to a certain height, its influence on the particle motion tends to be unchanged. And the barrier at the dissipative B lattice has little effect on the dynamics.
{"title":"Dissipation-Induced Recurrence of Non-Hermitian Edge Burst","authors":"Ren Cui-Cui, Yin Xiang-Guo","doi":"10.7498/aps.72.20230338","DOIUrl":"https://doi.org/10.7498/aps.72.20230338","url":null,"abstract":"In quantum mechanics, the Hermitian Hamiltonian is generally used to describe the ideal closed quantum system, but in reality, the physical system is closely related to the environment, and the open quantum system coupled to the environment can be described by the equivalent non-Hermitian Hamiltonian to a certain extent. Among them, the dissipation intensity is closely related to the dynamic properties of non-Hermitian quantum systems. Therefore, it is of great practical significance to study how dissipation affects particle loss. In this paper, the dynamic law related to dissipation intensity in one-dimensional non-Hermitian systems under open boundary conditions is studied, and it is found that dissipation can induce the recurrence of edge burst. After the time-dependent evolution of the particles in the one-dimensional non-Hermitian dissipative lattice system with open boundary conditions, there is an edge burst in the system, that is, there is a large probability of particle loss at the edge, and the edge burst disappears after increasing the intensity of intracellular transition. It is found that if the dissipation intensity is increased or decreased, the edge burst will reappear. This kind of reappearance is different from the original edge burst, which is mainly manifested in the loss probability distribution of particles from the edge distribution to the volume distribution, which is due to the different probability of particle motion direction in the two cases. Under the re-induced edge burst, the particles move from the initial position to the left and right directions, and the left side rebounds after reaching the boundary, forming a more obvious loss probability at the edge and gradually decreasing to the body area. In the original edge burst, the probability of particles only moving to the left is larger, and the 'trapped' is completely dissipated at the edge, forming a distribution with an independent loss peak at the edge, the movement to the left is due to due to the non-Hermitian skin effect. The deeper reason for different movement directions is related to the defect of non-Hermitian system far from parity-time symmetry breaking. Under the parameter near the parity-time symmetry breaking defect, the loss probability of the particle is unilateral distribution, and the loss probability of the particle moving to both sides is bilateral distribution when it is far away. This is the description of the dissipation-induced edge burst recurrence phenomenon and its characteristics. In addition, this paper also studies the influence of impurity barrier on the probability distribution of particle loss in non-Hermitian dynamics. The results show that placing a small barrier on the non-dissipative A-site can obviously hinder the particle motion, and when the barrier increases to a certain height, its influence on the particle motion tends to be unchanged. And the barrier at the dissipative B lattice has little effect on the dynamics.","PeriodicalId":6995,"journal":{"name":"物理学报","volume":"16 1","pages":""},"PeriodicalIF":1.0,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90132965","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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}
In a quantum system with spin, spin-orbit coupling is manifested by linking the spin angular momentum of a particle with its orbital angular momentum, which leads to many exotic phenomena. The experimental realization of synthetic spin-orbit coupling effects in ultra-cold atomic systems provides a completely new platform for exploring quantum simulations. In a spinor Bose-Einstein condensate, the spin-orbit coupling can change the properties of the system significantly, which offers a great opportunity to investigate the influence of spin-orbit coupling to the quantum state at the macroscopic level. As typical states of macroscopic quantum effects, solitons in spin-orbit coupled Bose-Einstein condensates can be manipulated by spin-orbit coupling directly, this makes the study on spin-orbit coupled Bose-Einstein condensates become one of the hottest topics in the research of ultracold atomic physics in recent years. This paper investigates exact vector soliton solutions of the Gross-Pitaevskii equation for the one-dimensional spin-orbit coupled binary Bose-Einstein condensates, which has four parameters μ,δ,α and β, where μ denotes the strength of the spin-orbit coupling, δ is the detuning parameter,α and β are the parameters of the self-and cross-interaction, respectively. For the case β=α, by a direct ansatz, two kinds of stripe solitons, namely, the oscillating dark-dark solitons are obtained; meanwhile, a transformation is presented such that from the solutions of the integrable Manakov system, one can get soliton solutions for the spin-orbit coupled Gross-Pitaevskii equation. For the case β=3α, a bright-W type soliton for α>0 and a kink-antikink type soliton for α<0 are presented. It is found that the relation between μ and δ can affect the states of the solitons. Based on these solutions, the corresponding dynamics and the impact of the spin-orbit coupling effects on the quantum magnetization and spin-polarized domains are discussed. Our results show that spin-orbit coupling can result in rich kinds of soliton states in the two-component Bose gases, including the stripe solitons as well as the classical non-stripe solitons, and various kinds of multi-solitons. Furthermore, spin-orbit coupling has remarkable influence on the behaviors of quantum magnetization. In the experiments of Bose-Einstein condensates, there have been many different methods to observe the soliton states of the population distribution, the magnetic solitons, and the spin domains, so our results provide some possible options for the related experiments.
{"title":"Soliton Solutions of the Spin-Orbit Coupled Binary Bose-Einstein Condensate System","authors":"Li Xin-Yue, Qi Juan-Juan, Zhao Dun, Liu Wu-ming","doi":"10.7498/aps.72.20222319","DOIUrl":"https://doi.org/10.7498/aps.72.20222319","url":null,"abstract":"In a quantum system with spin, spin-orbit coupling is manifested by linking the spin angular momentum of a particle with its orbital angular momentum, which leads to many exotic phenomena. The experimental realization of synthetic spin-orbit coupling effects in ultra-cold atomic systems provides a completely new platform for exploring quantum simulations. In a spinor Bose-Einstein condensate, the spin-orbit coupling can change the properties of the system significantly, which offers a great opportunity to investigate the influence of spin-orbit coupling to the quantum state at the macroscopic level. As typical states of macroscopic quantum effects, solitons in spin-orbit coupled Bose-Einstein condensates can be manipulated by spin-orbit coupling directly, this makes the study on spin-orbit coupled Bose-Einstein condensates become one of the hottest topics in the research of ultracold atomic physics in recent years. This paper investigates exact vector soliton solutions of the Gross-Pitaevskii equation for the one-dimensional spin-orbit coupled binary Bose-Einstein condensates, which has four parameters μ,δ,α and β, where μ denotes the strength of the spin-orbit coupling, δ is the detuning parameter,α and β are the parameters of the self-and cross-interaction, respectively. For the case β=α, by a direct ansatz, two kinds of stripe solitons, namely, the oscillating dark-dark solitons are obtained; meanwhile, a transformation is presented such that from the solutions of the integrable Manakov system, one can get soliton solutions for the spin-orbit coupled Gross-Pitaevskii equation. For the case β=3α, a bright-W type soliton for α>0 and a kink-antikink type soliton for α<0 are presented. It is found that the relation between μ and δ can affect the states of the solitons. Based on these solutions, the corresponding dynamics and the impact of the spin-orbit coupling effects on the quantum magnetization and spin-polarized domains are discussed. Our results show that spin-orbit coupling can result in rich kinds of soliton states in the two-component Bose gases, including the stripe solitons as well as the classical non-stripe solitons, and various kinds of multi-solitons. Furthermore, spin-orbit coupling has remarkable influence on the behaviors of quantum magnetization. In the experiments of Bose-Einstein condensates, there have been many different methods to observe the soliton states of the population distribution, the magnetic solitons, and the spin domains, so our results provide some possible options for the related experiments.","PeriodicalId":6995,"journal":{"name":"物理学报","volume":"6 1","pages":""},"PeriodicalIF":1.0,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90188703","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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}
Chen Qi, Dai Yue, Li Fei-Yan, Zhang Biao, Li Hao-Chen, Tan Jing-Rou, Wang Xiao-Han, He Guang-Long, Fei Yue, Wang Hao, Zhang La-Bao, Kang Lin, Chen Jian, Wu Pei-heng
High-performance mid-wave and long-wave infrared single-photon detectors not only have significant research value in the fields of infrared astronomy and defense technology, but are also challenging to be realized in the field of single-photon detection technology. Superconducting nanowire single-photon detectors (SNSPDs) have shown excellent performance in the near-infrared band. However, how to further improve the cutoff wavelength λc is a topic of widespread concern. In this paper, the method for improving λc by applying the regulation of the superconducting disorder is discussed, and a detector with an operating wavelength band of 5 - 10 μm is designed and fabricated. Studies have shown that the multiplication and diffusion behaviors of the quasiparticles always occur during the photon detection events, although the microscopic photodetection mechanism of SNSPD still lacks a perfect theoretical explanation. Therefore, the theoretical analysis mainly considers the influence of the quasiparticles in this paper, and the mathematical formula of the detection cutoff wavelength λc can be obtained based on the phenomenological quasiparticle diffusion model. Furthermore, the disorder-dependent superconducting phase transition temperature Tc, superconducting energy gap D, and electron thermalization time τth are also considered, in order to get more precise results.Theoretical analysis suggests that the increase in the sheet resistance Rs, which evaluates the disorder strength, will help to increase λc. For example, when the nanowire width is kept at 30 nm and Rs > 380 Ω/□, it can be deduced that λc is larger than 10 μm.Experimentally, the active area of the device consists of a straight superconducting nanowire with a length of 10 μm and a width of 30 nm, so that it can effectively reduce the probability of the defects on the nanowire and avoid the current crowding effect. We have fabricated a 30 nm-wide Mo0.8Si0.2 mid infrared SNSPD, which has a cutoff wavelength λc no more than 5 μm, the effective strength of the disorder - the film sheet resistance Rs = 248.6 Ω/□. As a comparison, the sheet resistance, which is controlled by the film thickness, is increased to about 320 Ω/□ in this experiment.It is demonstrated that the Mo0.8Si0.2 detector with Rs ~320 Ω/□ can achieve saturated quantum efficiency at a wavelength of 6 μm. Furthermore, 53% quantum efficiency at the wavelength of 10.2 μm can be obtained when the detector works at a bias current of 0.9 ISW (ISW is the superconducting transition current), and it can theoretically reach a maximum value of 92% if the compression of switching current is excluded. Therefore, it can be predicted that the disorder regulation may become another efficient approach for designing high-performance mid-wave and long-wave infrared SNSPDs, in addition to the optimization of the superconducting energy gap and the cross section of superconducting nanowire.However, the continuous increase in the disorder will cause a d
{"title":"Design and fabrication of the superconducting single-photon detector operating at the 5 - 10 micrometer wavelength band","authors":"Chen Qi, Dai Yue, Li Fei-Yan, Zhang Biao, Li Hao-Chen, Tan Jing-Rou, Wang Xiao-Han, He Guang-Long, Fei Yue, Wang Hao, Zhang La-Bao, Kang Lin, Chen Jian, Wu Pei-heng","doi":"10.7498/aps.72.20221594","DOIUrl":"https://doi.org/10.7498/aps.72.20221594","url":null,"abstract":"High-performance mid-wave and long-wave infrared single-photon detectors not only have significant research value in the fields of infrared astronomy and defense technology, but are also challenging to be realized in the field of single-photon detection technology. Superconducting nanowire single-photon detectors (SNSPDs) have shown excellent performance in the near-infrared band. However, how to further improve the cutoff wavelength λc is a topic of widespread concern. In this paper, the method for improving λc by applying the regulation of the superconducting disorder is discussed, and a detector with an operating wavelength band of 5 - 10 μm is designed and fabricated. Studies have shown that the multiplication and diffusion behaviors of the quasiparticles always occur during the photon detection events, although the microscopic photodetection mechanism of SNSPD still lacks a perfect theoretical explanation. Therefore, the theoretical analysis mainly considers the influence of the quasiparticles in this paper, and the mathematical formula of the detection cutoff wavelength λc can be obtained based on the phenomenological quasiparticle diffusion model. Furthermore, the disorder-dependent superconducting phase transition temperature Tc, superconducting energy gap D, and electron thermalization time τth are also considered, in order to get more precise results.Theoretical analysis suggests that the increase in the sheet resistance Rs, which evaluates the disorder strength, will help to increase λc. For example, when the nanowire width is kept at 30 nm and Rs > 380 Ω/□, it can be deduced that λc is larger than 10 μm.Experimentally, the active area of the device consists of a straight superconducting nanowire with a length of 10 μm and a width of 30 nm, so that it can effectively reduce the probability of the defects on the nanowire and avoid the current crowding effect. We have fabricated a 30 nm-wide Mo0.8Si0.2 mid infrared SNSPD, which has a cutoff wavelength λc no more than 5 μm, the effective strength of the disorder - the film sheet resistance Rs = 248.6 Ω/□. As a comparison, the sheet resistance, which is controlled by the film thickness, is increased to about 320 Ω/□ in this experiment.It is demonstrated that the Mo0.8Si0.2 detector with Rs ~320 Ω/□ can achieve saturated quantum efficiency at a wavelength of 6 μm. Furthermore, 53% quantum efficiency at the wavelength of 10.2 μm can be obtained when the detector works at a bias current of 0.9 ISW (ISW is the superconducting transition current), and it can theoretically reach a maximum value of 92% if the compression of switching current is excluded. Therefore, it can be predicted that the disorder regulation may become another efficient approach for designing high-performance mid-wave and long-wave infrared SNSPDs, in addition to the optimization of the superconducting energy gap and the cross section of superconducting nanowire.However, the continuous increase in the disorder will cause a d","PeriodicalId":6995,"journal":{"name":"物理学报","volume":"85 1","pages":""},"PeriodicalIF":1.0,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90589201","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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}
Zhang Pu-Du, Wang Wei-Quan, Li Zhe-Min, Zhang Zi-Xuan, Wang Ye-Chen, Zhou Hong-Yu, Yin Yan
Laser-driven ion acceleration has potential applications in high energy density matter, ion beam-driven fast ignition, beam target neutron source and warm dense matter heating and etc. Ultrashort relativistic lasers interacting with solid targets can generate ion beams with energies up to several hundreds of MeV, and the quality of the ion beams strongly depends on the interaction parameters of the laser and the targets. Developments in deep learning can provide new methods in the analysis of relationship between parameters in physics systems, which can significantly reduce the computational and experimental cost. In this paper, a continuous mapping model of ion peak and cutoff energies is developed based on a fully connected neural network(FCNN). In the model, the dataset is composed of nearly 400 sets of particle simulations of laser-driven solid targets, and the input parameters are laser intensity, target density, target thickness and ion mass. The model obtains the parameter analysis results in a large range of values with sparser parameter taking values, which greatly reduces the computational effort of sweeping the parameters in a large range of multi-dimensional parameters. Based on the results of this model mapping, the correction formula for the ion peak energy over ion mass is obtained. Furthermore, the ratio of ion cutoff energy and peak energy of each set of particle simulation is calculated. Repeating the same training process of ion peak energy and cutoff energy, the continuous mapping model of energy ratio is developed. According to the energy ratio model mapping results, the quantitative description of the relationship between ion cutoff energy and peak energy is realized, and the fitting formula for the cutoff energy of the Hole-Boring Radiation Pressure Acceleration (HB-RPA) mechanism is obtained, which can provide an important reference for the laser-driven ion acceleration experiments design.
{"title":"Deep Learning-Based Hole-Boring Radiation Pressure Ion Acceleration Modeling","authors":"Zhang Pu-Du, Wang Wei-Quan, Li Zhe-Min, Zhang Zi-Xuan, Wang Ye-Chen, Zhou Hong-Yu, Yin Yan","doi":"10.7498/aps.72.20230702","DOIUrl":"https://doi.org/10.7498/aps.72.20230702","url":null,"abstract":"Laser-driven ion acceleration has potential applications in high energy density matter, ion beam-driven fast ignition, beam target neutron source and warm dense matter heating and etc. Ultrashort relativistic lasers interacting with solid targets can generate ion beams with energies up to several hundreds of MeV, and the quality of the ion beams strongly depends on the interaction parameters of the laser and the targets. Developments in deep learning can provide new methods in the analysis of relationship between parameters in physics systems, which can significantly reduce the computational and experimental cost. In this paper, a continuous mapping model of ion peak and cutoff energies is developed based on a fully connected neural network(FCNN). In the model, the dataset is composed of nearly 400 sets of particle simulations of laser-driven solid targets, and the input parameters are laser intensity, target density, target thickness and ion mass. The model obtains the parameter analysis results in a large range of values with sparser parameter taking values, which greatly reduces the computational effort of sweeping the parameters in a large range of multi-dimensional parameters. Based on the results of this model mapping, the correction formula for the ion peak energy over ion mass is obtained. Furthermore, the ratio of ion cutoff energy and peak energy of each set of particle simulation is calculated. Repeating the same training process of ion peak energy and cutoff energy, the continuous mapping model of energy ratio is developed. According to the energy ratio model mapping results, the quantitative description of the relationship between ion cutoff energy and peak energy is realized, and the fitting formula for the cutoff energy of the Hole-Boring Radiation Pressure Acceleration (HB-RPA) mechanism is obtained, which can provide an important reference for the laser-driven ion acceleration experiments design.","PeriodicalId":6995,"journal":{"name":"物理学报","volume":"26 1","pages":""},"PeriodicalIF":1.0,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90636821","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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}
Luo Jie, Zhang Zi-Qiu, Xu Jun-Hao, Qin Zhao-Ting, Zhao Yuan-Shuai, He Hong, Li Guan-Nan, Tang Jian-Feng
A series of rare earth Dy3+, Tb3+, Eu3+ singly doped Gd2Te4O11 (GTO) tellurite phosphors with intrinsic polarity were prepared by hydrothermal method. The phase structure, morphology and thermal stability of the phosphors were characterized. Their luminescence properties were tested in detail. The results show all those phosphors were crystalized into single phase of digadolinium tellurite with short rod-like shape. The maximum size achieved microns in axial direction. The phosphors have good thermal stability. For the GTO:Dy3+, the fluorescence emission under UV excitation is mainly located in the yellow-green region. The optimal doping concentration corresponding to the strongest excitation and emission is 2.5%, and the CIE color coordinates are (0.39, 0.43). The fluorescence decay curves show that the lifetime of the GTO:Dy3+ on 4F9/2 energy level decreases gradually with increasing doping concentration of Dy3+, which may be related to the cross relaxation (CR) between Dy3+ ions. For the GTO:Eu3+, the fluorescence emission under UV excitation is mainly located in the red and orange-red regions. The emission intensity was enhanced with increasing doping concentration of Eu3+. When the doping concentration is 10%, the CIE color coordinates are (0.62, 0.38), which located in the orange-red region with high color purity. The fluorescence lifetime of Eu3+ on 5D0 energy level is hardly affected by the change of Eu3+ doping concentration. For the GTO:Tb3+, with increasing the Tb3+ concentration, the fluorescence emission under UV excitation changes from blue-violet region to yellow-green region, which can be ascribed to the influence of CR between Tb3+ ions. The fluorescence decay behavior revealed that the Tb3+ ions on 5D4 excited state may undergo energy transfer and reabsorption, which deviated fluorescence decay from the single exponential model. When the concentration of Tb3+ is 0.5%, the sample exhibits white light emission, having the CIE color coordinates of (0.33, 0.35) and color rendering index of 86. The measurements of temperature-dependent emission spectra show that the above-mentioned phosphors have good luminescent thermal stability. The internal quantum efficiencies (IQE) of those three types of phosphors were tested, and the IQE of GTO:Eu3+ are better than those of GTO:Dy3+ and GTO:Tb3+. All those phosphors still have much room for improvement in the luminescent performance. These phosphors have potential for the use of UV-excited white LED.
{"title":"Synthesis and luminescent properties of rare earths doped Gd2Te4O11 tellurite phosphors","authors":"Luo Jie, Zhang Zi-Qiu, Xu Jun-Hao, Qin Zhao-Ting, Zhao Yuan-Shuai, He Hong, Li Guan-Nan, Tang Jian-Feng","doi":"10.7498/aps.72.20221341","DOIUrl":"https://doi.org/10.7498/aps.72.20221341","url":null,"abstract":"A series of rare earth Dy<sup>3+</sup>, Tb<sup>3+</sup>, Eu<sup>3+</sup> singly doped Gd<sub>2</sub>Te<sub>4</sub>O<sub>11</sub> (GTO) tellurite phosphors with intrinsic polarity were prepared by hydrothermal method. The phase structure, morphology and thermal stability of the phosphors were characterized. Their luminescence properties were tested in detail. The results show all those phosphors were crystalized into single phase of digadolinium tellurite with short rod-like shape. The maximum size achieved microns in axial direction. The phosphors have good thermal stability. For the GTO:Dy<sup>3+</sup>, the fluorescence emission under UV excitation is mainly located in the yellow-green region. The optimal doping concentration corresponding to the strongest excitation and emission is 2.5%, and the CIE color coordinates are (0.39, 0.43). The fluorescence decay curves show that the lifetime of the GTO:Dy<sup>3+</sup> on <sup>4</sup>F<sub>9/2</sub> energy level decreases gradually with increasing doping concentration of Dy<sup>3+</sup>, which may be related to the cross relaxation (CR) between Dy<sup>3+</sup> ions. For the GTO:Eu<sup>3+</sup>, the fluorescence emission under UV excitation is mainly located in the red and orange-red regions. The emission intensity was enhanced with increasing doping concentration of Eu<sup>3+</sup>. When the doping concentration is 10%, the CIE color coordinates are (0.62, 0.38), which located in the orange-red region with high color purity. The fluorescence lifetime of Eu<sup>3+</sup> on <sup>5</sup>D<sub>0</sub> energy level is hardly affected by the change of Eu<sup>3+</sup> doping concentration. For the GTO:Tb<sup>3+</sup>, with increasing the Tb<sup>3+</sup> concentration, the fluorescence emission under UV excitation changes from blue-violet region to yellow-green region, which can be ascribed to the influence of CR between Tb<sup>3+</sup> ions. The fluorescence decay behavior revealed that the Tb<sup>3+</sup> ions on <sup>5</sup>D<sub>4</sub> excited state may undergo energy transfer and reabsorption, which deviated fluorescence decay from the single exponential model. When the concentration of Tb<sup>3+</sup> is 0.5%, the sample exhibits white light emission, having the CIE color coordinates of (0.33, 0.35) and color rendering index of 86. The measurements of temperature-dependent emission spectra show that the above-mentioned phosphors have good luminescent thermal stability. The internal quantum efficiencies (IQE) of those three types of phosphors were tested, and the IQE of GTO:Eu<sup>3+</sup> are better than those of GTO:Dy<sup>3+</sup> and GTO:Tb<sup>3+</sup>. All those phosphors still have much room for improvement in the luminescent performance. These phosphors have potential for the use of UV-excited white LED.","PeriodicalId":6995,"journal":{"name":"物理学报","volume":"10 1","pages":""},"PeriodicalIF":1.0,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90822671","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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}
Wang Jing Jiao Yang Tian Wen-De Chen Kang, 焦阳, 田文得, 陈康
Active matter refers to a class of substances capable of autonomously moving by harnessing energy from their surrounding environment. These substances exhibit unique non-equilibrium phenomena, and hence have attracted great attention in the scientific community. Many active matters, such as bacteria, cells, micro-swimmers, and self-propelled colloidal particles, operate in viscous environment and their motions are usually described using overdamped models. Examples include overdamped active Brownian particle (ABP) model for self-propelled colloidal particles in solution and run-and-tumble (RTP) model for swimming bacteria. In recent years, increasing research studies have focused on the impact of inertia on the behavior of active matter. Vibrating robots, runners, flying insects, and micro-fliers are example active systems in the underdamped condition. The motion of these active matters can be modelled by underdamped Langevin equation, known as the active inertial particle (AIP) model. Previous studies have demonstrated that, similar to ABP systems, motility-induced phase separation (MIPS) phenomena also happen in AIP systems under certain density conditions. However, due to the strong collision-and-rebound effect, aggregation of AIP particles and hence the MIPS are impeded. In complex living/application environments, mixture of different active agents is often seen. Some studies on mixed systems of active matter show that the composition is an important quantity, influencing the phase separation phenomena. In this paper, we study the phase separation phenomena in mixed systems composed of low- and high-inertia active particles by underdamped Langevin dynamics simulations. We find that, compared to single-component system, the mixed systems are unexpectedly more favorable for the occurrence of phase separation at moderate overall concentration and certain range of component fraction, while more unfavorable for phase separation at high overall concentration. The underlying mechanism is that the presence of a small amount of the high-inertia particles could accelerate the motion of the low-inertia particles, and hence facilitate their aggregation and promote the phase separation. However, when the fraction of the high-inertia particles is large, frequent elastic collisions would disturb the aggregation of the low-inertia particles and suppress the occurrence of phase separation. Our results provide new sights into the collective behavior of active materials and also a reference for their design and applications.
{"title":"Phase separation in mixed systems of active particles with low and high inertia","authors":"Wang Jing Jiao Yang Tian Wen-De Chen Kang, 焦阳, 田文得, 陈康","doi":"10.7498/aps.72.20230792","DOIUrl":"https://doi.org/10.7498/aps.72.20230792","url":null,"abstract":"Active matter refers to a class of substances capable of autonomously moving by harnessing energy from their surrounding environment. These substances exhibit unique non-equilibrium phenomena, and hence have attracted great attention in the scientific community. Many active matters, such as bacteria, cells, micro-swimmers, and self-propelled colloidal particles, operate in viscous environment and their motions are usually described using overdamped models. Examples include overdamped active Brownian particle (ABP) model for self-propelled colloidal particles in solution and run-and-tumble (RTP) model for swimming bacteria. In recent years, increasing research studies have focused on the impact of inertia on the behavior of active matter. Vibrating robots, runners, flying insects, and micro-fliers are example active systems in the underdamped condition. The motion of these active matters can be modelled by underdamped Langevin equation, known as the active inertial particle (AIP) model. Previous studies have demonstrated that, similar to ABP systems, motility-induced phase separation (MIPS) phenomena also happen in AIP systems under certain density conditions. However, due to the strong collision-and-rebound effect, aggregation of AIP particles and hence the MIPS are impeded. In complex living/application environments, mixture of different active agents is often seen. Some studies on mixed systems of active matter show that the composition is an important quantity, influencing the phase separation phenomena. In this paper, we study the phase separation phenomena in mixed systems composed of low- and high-inertia active particles by underdamped Langevin dynamics simulations. We find that, compared to single-component system, the mixed systems are unexpectedly more favorable for the occurrence of phase separation at moderate overall concentration and certain range of component fraction, while more unfavorable for phase separation at high overall concentration. The underlying mechanism is that the presence of a small amount of the high-inertia particles could accelerate the motion of the low-inertia particles, and hence facilitate their aggregation and promote the phase separation. However, when the fraction of the high-inertia particles is large, frequent elastic collisions would disturb the aggregation of the low-inertia particles and suppress the occurrence of phase separation. Our results provide new sights into the collective behavior of active materials and also a reference for their design and applications.","PeriodicalId":6995,"journal":{"name":"物理学报","volume":"26 1","pages":""},"PeriodicalIF":1.0,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86842477","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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}
By combining plane waves with Gaussian or spline functions, this paper constructs a new composite basis set. As a non local basis vector, the plane wave basis group needs a large number of plane waves to expand all parts of the physical space, including the intermediate regions that are not important to our problems. Our basis set uses the local characteristics of Gaussian function or spline function at the same time, and controls the energy interval by selecting different plane wave vectors, so as to realize the partition solution of Hamiltonian matrix. Orthogonal normalization of composite basis sets is performed using Gram-Schmidt's orthogonalization method or Löwdin's orthogonalization method. Considering the completeness of plane wave vector, a certain value of positive and negative should be selected at the same time. Here, by changing the absolute value of wave vector, we can select the eigenvalue interval to be solved. The plane wave with a specific wave vector value is equivalent to a trial solution in the region with gentle potential energy. The algorithm automatically combines local Gaussian or spline functions to match the wave vector value difference between the trial solution and the strict solution. By selecting the absolute value of the wave vector in the plane wave function, this paper turns the calculation of large Hamiltonian matrices into the calculation of multiple small matrices, together with reducing the basis numbers in the region where the electron potential changes smoothly, we can significantly reduce the computational time. As an example, we apply this basis set to a one-dimensional finite depth potential well, it can be found that our method significantly reduce the number of basis vectors used to expand the wave function while maintaining a suitable degree of computational accuracy. We also studied the impact of different parameters on calculation accuracy. Finally, the above calculation method can be directly applied to the DFT calculation of plasmons in silver nanoplates or other metal nanostructures. Given a reasonable tentative initial state, the ground state electron density distribution of the system can be solved by self consistent solution using DFT theory, and then the electromagnetic field distribution and optical properties of the system can be solved using time-dependent density functional theory theory (TDDFT).
{"title":"Composite Basis Set of Plane Wave and Gaussian Function or Spline Function","authors":"Zhang Guang-Di, Mao Li, Xu Hong-Xing","doi":"10.7498/aps.72.20230872","DOIUrl":"https://doi.org/10.7498/aps.72.20230872","url":null,"abstract":"By combining plane waves with Gaussian or spline functions, this paper constructs a new composite basis set. As a non local basis vector, the plane wave basis group needs a large number of plane waves to expand all parts of the physical space, including the intermediate regions that are not important to our problems. Our basis set uses the local characteristics of Gaussian function or spline function at the same time, and controls the energy interval by selecting different plane wave vectors, so as to realize the partition solution of Hamiltonian matrix. Orthogonal normalization of composite basis sets is performed using Gram-Schmidt's orthogonalization method or Löwdin's orthogonalization method. Considering the completeness of plane wave vector, a certain value of positive and negative should be selected at the same time. Here, by changing the absolute value of wave vector, we can select the eigenvalue interval to be solved. The plane wave with a specific wave vector value is equivalent to a trial solution in the region with gentle potential energy. The algorithm automatically combines local Gaussian or spline functions to match the wave vector value difference between the trial solution and the strict solution. By selecting the absolute value of the wave vector in the plane wave function, this paper turns the calculation of large Hamiltonian matrices into the calculation of multiple small matrices, together with reducing the basis numbers in the region where the electron potential changes smoothly, we can significantly reduce the computational time. As an example, we apply this basis set to a one-dimensional finite depth potential well, it can be found that our method significantly reduce the number of basis vectors used to expand the wave function while maintaining a suitable degree of computational accuracy. We also studied the impact of different parameters on calculation accuracy. Finally, the above calculation method can be directly applied to the DFT calculation of plasmons in silver nanoplates or other metal nanostructures. Given a reasonable tentative initial state, the ground state electron density distribution of the system can be solved by self consistent solution using DFT theory, and then the electromagnetic field distribution and optical properties of the system can be solved using time-dependent density functional theory theory (TDDFT).","PeriodicalId":6995,"journal":{"name":"物理学报","volume":"1 1","pages":""},"PeriodicalIF":1.0,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86919790","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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}
Liu Yun, Wang Wen-Hai, He De-Jing, Zhou Yong-Zhuang, Shen Yong, Zou Hong-Xin
The first space optical clock (SOC) in the world developed in China, which is composed by five subsystems, including an optical unit, a physics unit, an electronic control unit, a space optical frequency comb, and an ultrastable laser, has been successfully launched with the Mengtian space laboratory into the China Space Station (CSS). Compact and stable lasers are key elements for the operation of the SOC. The optical unit consists of 5 lasers at 461 nm, 679 nm, 689 nm, 707nm, and 813 nm. With a synchronous-tuning-like scheme, high quality external cavity diode lasers (ECDL) have been developed as the seeds. The linewidth of the lasers is suppressed to the order of 100 kHz, and the mode-hop-free tuning range reaches 20 GHz, which meet the requirements of the SOC. With careful mechanical and thermal design, the stability of the lasers against vibration and temperature fluctuation has been sufficiently promoted to confront the challenge of rocket launching. While the power from the ECDL is sufficient for 679 nm and 707 nm repump lasers, additional injection lock is utilized for the 461 nm and 689 nm lasers to amplify the power of the seeds to more than 600 mW, so that efficient first and second stage Doppler cooling can be achieved. To generate an optical lattice with deep enough potential well, over 800 mW 813 nm lasers is required. Therefore, a semiconductor tapered amplifier is adopted to amplify the seed to more than 2 W, so as to cope with various losses of the coupling optics. The wavelength and output power of the 5 lasers are monitored and feedback-controlled by the electronic control unit. All the modules are designed and manufactured as orbital replaceable units, which can be easily replaced by astronauts in case failure occurs. Now the lasers are all turned on and operates normally in CSS. More data of the SOC will be obtained in the near future. At present stage, according to our evaluation, the continuous operation time of the SOC is limited by the injection locked lasers, which are relatively vulnerable to mode hopping. Hopefully this problem can be solved by improving the laser diode manufacturing technology, or developing fiber lasers with compact frequency conversion modules.
{"title":"Research progress on the laser system of the cold atomic clock in China Space Station","authors":"Liu Yun, Wang Wen-Hai, He De-Jing, Zhou Yong-Zhuang, Shen Yong, Zou Hong-Xin","doi":"10.7498/aps.72.20230412","DOIUrl":"https://doi.org/10.7498/aps.72.20230412","url":null,"abstract":"The first space optical clock (SOC) in the world developed in China, which is composed by five subsystems, including an optical unit, a physics unit, an electronic control unit, a space optical frequency comb, and an ultrastable laser, has been successfully launched with the Mengtian space laboratory into the China Space Station (CSS). Compact and stable lasers are key elements for the operation of the SOC. The optical unit consists of 5 lasers at 461 nm, 679 nm, 689 nm, 707nm, and 813 nm. With a synchronous-tuning-like scheme, high quality external cavity diode lasers (ECDL) have been developed as the seeds. The linewidth of the lasers is suppressed to the order of 100 kHz, and the mode-hop-free tuning range reaches 20 GHz, which meet the requirements of the SOC. With careful mechanical and thermal design, the stability of the lasers against vibration and temperature fluctuation has been sufficiently promoted to confront the challenge of rocket launching. While the power from the ECDL is sufficient for 679 nm and 707 nm repump lasers, additional injection lock is utilized for the 461 nm and 689 nm lasers to amplify the power of the seeds to more than 600 mW, so that efficient first and second stage Doppler cooling can be achieved. To generate an optical lattice with deep enough potential well, over 800 mW 813 nm lasers is required. Therefore, a semiconductor tapered amplifier is adopted to amplify the seed to more than 2 W, so as to cope with various losses of the coupling optics. The wavelength and output power of the 5 lasers are monitored and feedback-controlled by the electronic control unit. All the modules are designed and manufactured as orbital replaceable units, which can be easily replaced by astronauts in case failure occurs. Now the lasers are all turned on and operates normally in CSS. More data of the SOC will be obtained in the near future. At present stage, according to our evaluation, the continuous operation time of the SOC is limited by the injection locked lasers, which are relatively vulnerable to mode hopping. Hopefully this problem can be solved by improving the laser diode manufacturing technology, or developing fiber lasers with compact frequency conversion modules.","PeriodicalId":6995,"journal":{"name":"物理学报","volume":"1973 1","pages":""},"PeriodicalIF":1.0,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90245015","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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}
Shu-Peng Sun, Yongzhi Cheng, Hui Luo, Fu Chen, Xiangcheng Li
In this paper, a compact broadband bandpass filter with wide out-of-band rejection characteristics based on halberd-shaped spoof surface plasmon polariton (SSPP) is proposed. The filtering structure is achieved by etching a periodic halberd-shaped groove at the bottom of the substrate and a microstrip-to-slot line transition with a crescent-shaped patch at the top. Compared with the traditional dumbbell-shaped SSPP, the halberd-shaped SSPP has good slow-wave property, and the designed bandpass filter based on halberd-shaped SSPP can achieve a more compact size. The upper cutoff frequency and lower cutoff frequency of the passband can be adjusted by regulating the SSPP structure and the transition structure from microstrip-to-slot line, respectively. The simulation results show that the center frequency of broadband bandpass filter is 2.85 GHz, with the relative bandwidth of 130%, and the return loss in the passband is better than –10 dB, and the extreme strong out-of-band rejection of –40 dB from 5.6 GHz to 20 GHz. The size of the broadband bandpass filter is compact, only 1.08λg×0.39λg, where λg is the wavelength at the center frequency. In order to verify the effectiveness of the wideband bandpass filter, the traditional printed circuit board technology is used to fabricate the wideband bandpass filter. The measurement results are in good agreement with the simulation results, verifying the feasibility of the design. The proposed broadband bandpass filter shows promising prospects for developing SSPP functional devices and circuits at microwave frequencies.
{"title":"Compact broadband bandpass filter with wide stopband based on halberd-shaped spoof surface plasmon polariton","authors":"Shu-Peng Sun, Yongzhi Cheng, Hui Luo, Fu Chen, Xiangcheng Li","doi":"10.7498/aps.72.20222291","DOIUrl":"https://doi.org/10.7498/aps.72.20222291","url":null,"abstract":"In this paper, a compact broadband bandpass filter with wide out-of-band rejection characteristics based on halberd-shaped spoof surface plasmon polariton (SSPP) is proposed. The filtering structure is achieved by etching a periodic halberd-shaped groove at the bottom of the substrate and a microstrip-to-slot line transition with a crescent-shaped patch at the top. Compared with the traditional dumbbell-shaped SSPP, the halberd-shaped SSPP has good slow-wave property, and the designed bandpass filter based on halberd-shaped SSPP can achieve a more compact size. The upper cutoff frequency and lower cutoff frequency of the passband can be adjusted by regulating the SSPP structure and the transition structure from microstrip-to-slot line, respectively. The simulation results show that the center frequency of broadband bandpass filter is 2.85 GHz, with the relative bandwidth of 130%, and the return loss in the passband is better than –10 dB, and the extreme strong out-of-band rejection of –40 dB from 5.6 GHz to 20 GHz. The size of the broadband bandpass filter is compact, only 1.08λg×0.39λg, where λg is the wavelength at the center frequency. In order to verify the effectiveness of the wideband bandpass filter, the traditional printed circuit board technology is used to fabricate the wideband bandpass filter. The measurement results are in good agreement with the simulation results, verifying the feasibility of the design. The proposed broadband bandpass filter shows promising prospects for developing SSPP functional devices and circuits at microwave frequencies.","PeriodicalId":6995,"journal":{"name":"物理学报","volume":"38 1","pages":""},"PeriodicalIF":1.0,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90347562","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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}
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