检索结果-内蒙古大学图书馆

Role of molecular alignment in attosecond photoionization of N2

Physical Review A 2023年第1期108卷 013113-013113页

作者： Ru Zhang Feng Wang Qing Liao Peixiang Lu Hubei Key Laboratory of Optical Information and Pattern Recognition Wuhan Institute of Technology Wuhan 430205 China Guangdong Intelligent Robotics Institute Dongguan 523808 China

We theoretically study the influence of molecular alignment on the attosecond photoionization of the N2 molecule. Based on the numerical simulations of the single-active-electron two-dimensional time-dependent Schrödinger equation, we find that the alignment-averaged photoelectron momentum distributions deviate from the single-molecule result, especially for a large molecular alignment angle and a low degree of molecular alignment. As a result, the photoemission time delays extracted from the angular-averaged streaking spectra are different from the single-molecule result. More importantly, the alignment-averaged photoemission time delays are found to depend on the degree of molecular alignment as well as the molecular alignment distribution. Our results reveal the important role of molecular alignment in the molecular attosecond photoionization.

关键词： Atomic & molecular processes in external fields Single- and few-photon ionization & excitation

来源：评论

学校读者我要写书评

暂无评论

Tmsf: Taylor Expansion Approximation Network with Multi-Stage Feature Representation for optical Flow Estimation

SSRN

引用

SSRN 2023年

作者： Zhu, Zifan Huang, Chen Xu, Biyun Xia, Menghan Fang, Hao Huang, Zhenghua Hubei Key Laboratory of Optical Information and Pattern Recognition Wuhan Institute of Technology Wuhan430205 China

optical flow estimation is a fundamental task in computer vision. Existing CNN-based and transformer-based methods have proven their powerful ability in generating preferable performance, but they still suffer from the loss of fine details and objects' shape. To cope with these problems, this paper develops a Taylor expansion approximation network with multi-stage feature representation, namely TMSF, including a basic network and a refine network. In the basic network, multi-stage modules, including feature enhancement module (FEM) for enriching image features, feature/context network for feature extraction, and iterative update module (IUM) for coarse optical flow estimation, are employed to represent fine features. In the refine network, a refinement architecture is constructed based on the third-order Taylor approximation expansion to further refine features from the basic network for optical flow, in which a feature attention module (FAM) is used to estimate each derivative layer. Meanwhile, a novel loss function is formed by end-point-error (EPE) and structural similarity (SSIM) to ensure our TMSF convergence to an enjoyable solution. Quantitative associated with qualitative experimental results validate that our TMSF performs better than state-of-the-art optical flow estimation methods on performance improvement and shape preservation. © 2023, The Authors. All rights reserved.

关键词： optical flows

来源：评论

学校读者我要写书评

暂无评论

Fine-grained Visual Classification by Progressive Training via Jigsaw Puzzle Permutation Learning 6

Fine-grained Visual Classification by Progressive Training v...

引用

6th International Conference on Communication, Image and Signal Processings, CCISP 2021

作者： Ma, Lei Zhao, Fan Hong, Hanyu Wu, Jinmeng Shi, Yu Li, Xuan Hubei Key Laboratory of Optical Information and Pattern Recognition Wuhan Institute of Technology Wuhan China

ISBN: (纸本)9781665432795

Fine-grained visual classification remains a challenging task due to small inter-class differences and large intra-class differences. Existing methods consider only local details of information or only global information at a certain stage. However, there methods do not consider the complementary relationship between local information of different granularity and global information of the overall object on the feature maps of different stages of the network. To solve the above problem, we propose a Progressively Trained Jigsaw Puzzle Permutation Learning network (PPL-Net). To obtain the local details of the object, we adopt a progressive training strategy to obtain the semantic information of the object. At different steps, we use different granularity of shuffled versions of the images as input. Then, the classification prediction is performed by fusing the feature representations of different granularities. We obtain the global information of the object by learning jigsaw puzzle visual permutation. Specifically, by introducing the Jigsaw Puzzle Solver module we explore the location information of the different granularity image patches. Recovery of the shuffled version of the image to the original image. Thus, at each step of the network, we supervise the network by complementary relationships between local information of different granularities and global information of the object. Experiments on three standard fine-grained classification datasets (CUB-200-2011, Stanford Cars, FGCV-Aircraft) show that the performance of our method exceeds that of most methods. The code will be available at https://***/Zhao-fan/PPL-Net. © 2021 IEEE

关键词： Semantics

来源：评论

学校读者我要写书评

暂无评论

Comparison study of laser vibration measurement and quantum vibration measurement 13

Comparison study of laser vibration measurement and quantum ...

引用

13th International Conference on Wireless Communications and Signal Processing, WCSP 2021

作者： Zhang, Chi Yang, Zi-Xiang Wang, Shun Jin, Rui-Bo Wuhan Institute of Technology Hubei Key Laboratory of Optical Information and Pattern Recognition Wuhan China

ISBN: (纸本)9781665407854

Vibration measurement plays an important role in the process of industrial production. How to measure the vibration with a high resolution is an important topic for the study of traditional laser Doppler vibrometers. With the development of quantum technology, it is possible to improve the measurement resolution to a higher level using the quantum entangled state. In this article, we built an experimental setup and measured a vibration source using a classical laser Doppler vibrometer. We also proposed an experimental scheme for quantum vibrometer using the NOON state. We compared the advantages and disadvantages of both schemes. As far as we know, this is the first quantum Doppler vibrometer scheme so far. © 2021 IEEE.

关键词： Vibration measurement

来源：评论

学校读者我要写书评

暂无评论

Encapsulation strategies on 2D materials for field effect transistors and photodetectors

引用

Chinese Chemical Letters 2022年第5期33卷 2281-2290页

作者： Wenjuan Huang Yue Zhang Mengting Song Bugao Wang Huayi Hou Xiaozong Hu Xiangbai Chen Tianyou Zhai Hubei Key Laboratory of Optical Information and Pattern Recognition Wuhan Institute of TechnologyWuhan 430205China State Key Laboratory of Materials Processing and Die&Mould Technology School of Materials Science and EngineeringHuazhong University of Science and TechnologyWuhan 430074China Green Catalysis Center College of ChemistryZhengzhou UniversityZhengzhou 450001China

Two-dimensional(2D)layered materials provide a promising alternative solution for overcoming the scal-ing limits in conventional Si-based ***,practical applications of 2D materials are facing crucial bottlenecks,particularly that arising from the instability under ambient *** studies of degradation mechanisms and protecting strategies for overcoming the ambient instability of 2D materials have attracted extensive research attentions,both experimentally and *** review attempts to provide an overview on the recent progress of the encapsulation strategies for 2D *** en-capsulation strategies of mechanical transfer,polymer capping,atomic layer deposition,in-situ oxidation,and surface functionalization are systematically discussed for improving the ambient stability of 2D *** addition,the current advances in air-stable and high-performance 2D materials-based field effect transistors(FETs)and photodetectors assisted by the encapsulation strategies are ***,the future directions of encapsulation techniques of 2D materials for FETs and photodetectors applications are suggested.

关键词： Two-dimensional materials Encapsulation Degradation Stability Field effect transistors Photodetectors

来源：评论

学校读者我要写书评

暂无评论

CTDPGAN: Infrared and Visible Image Fusion Using CNN-Transformer Dual-Process-Based Generative Adversarial Network

CTDPGAN: Infrared and Visible Image Fusion Using CNN-Transfo...

引用

Chinese Control Conference (CCC)

作者： Cheng Zhang Xuan Li Yuhang Xu Jie Wang Rongfu Chen Hubei Key Laboratory of Optical Information and Pattern Recognition China School of Electrical and Information Engineering Wuhan Institute of Technology

Most of the existing image fusion methods prefer to use the adversarial learning game to fuse infrared and visible imagess. However, such single adversarial mechanism makes image fusion task easily ignore global contextual information. To this end, this paper proposes a CNN-Transformer dual-process-based generative adversarial network (CTDPGAN) to fuse infrared and visible images. In generator, a dual-process-based module composed by a CNN block and a Swin-Transformer block is proposed. The channel filter and spatial filter in the CNN block has the ability to adaptively extract additional complementary information from images of various modalities while preserving the shallow features of the source images. The Swin-Transformer Block (STRB) is designed to establish local attention by dividing non-overlapping windows and then to bridge global attention by interacting windows. In addition, we introduce generative adversarial learning networks into the training process, the dual-channel transformer discriminators are designed to improve the discriminative ability of the fused image. Thus, the fused image learns the distribution of global contextual information from source images and retain competitive visible light and infrared domains in more balanced manner. Moreover, we introduce the primary and auxiliary feature concepts into the structural similarity loss function and spatial frequency loss function, which will enable the generator to produce a fused image that retains thermal radiation information and rich detail information. Finally, the experimental findings demonstrate that, in both subjective and objective assessments, our model produces outcomes that are equivalent to or superior compared to state-of-the-art image fusion methods.

关键词：

来源：评论

学校读者我要写书评

暂无评论

Surface-roughness-adjustable Au nanorods with strong plasmon absorption and abundant hotspots for improved SERS and photothermal performances

引用

Nano Research 2022年第3期15卷 2715-2721页

作者： Sijing Ding Liang Ma Jingru Feng Youlong Chen Dajie Yang Ququan Wang School of Mathematics and Physics China University of Geosciences(Wuhan)Wuhan 430074China Hubei Key Laboratory of Optical Information and Pattern Recognition Wuhan Institute of TechnologyWuhan 430205China Mathematics and Physics Department North China Electric Power UniversityBeijing 102206China Department of Physics Wuhan UniversityWuhan 430072China

The rational optimization of plasmonic property of metal nanocrystals by manipulating the structure and morphology is crucial for the plasmon-enhanced application and has always been an urgent ***,Au nanorods with tunable surface roughness are prepared by growing PbS,overgrowing Au,and dissolving PbS nanoparticles on the basis of smooth Au *** transverse plasmon resonance of Au nanorods is notably improved due to plasmon coupling between Au nanorods and the surface-modified Au nanoparticles,resulting in the strong and full-spectrum light *** simulations demonstrate that the surface-rough Au nanorods have abundant and full-surround hotspots coming from surface particle–particle plasmon coupling between ultrasmall nanogaps,sharp tips,and uneven areas on Au *** these characters,the surface-roughness-adjustable Au nanorods possess high tunability and enhancement of surface-enhanced Raman scattering(SERS)detection of Rhodamine B and significantly improved photothermal conversion *** nanorods with the largest surface roughness have the highest Raman enhancement factor both at 532 and 785 nm laser ***,photothermal conversion experiments under near-infrared(808 nm)and simulated sunlight irradiation confirm that the Au nanorods with rough surface have prominent photothermal conversion efficiency and can be regarded as promising candidates for photothermal therapy and solar-driven water evaporation.

关键词： Au nanorods SERS plasmon resonance photothermal conversion near-field enhancement

来源：评论

学校读者我要写书评

暂无评论

Extracting the phase distribution of the electron wave packet ionized by an elliptically polarized laser pulse

引用

Frontiers of physics 2021年第3期16卷 185-192页

作者： Ya-Nan Qin Min Li Yudi Feng Siqiang Luo Yueming Zhou Peixiang Lu Wuhan National Laboratory for Optoelectronics and School of Physics Huazhong University of Science and TechnologyWuhan430074China Hubei Key Laboratory of Optical Information and Pattern Recognition Wuhan Institute of TechnologyWuhan430205China

We use an interferometic scheme to extract the phase distribution of the electron wave packet from above-threshold ionization in elliptically polarized laser *** this scheme,an electron wave packet released from a circularly polarized laser pulse acts as a reference wave and interferes with the electron wave packet ionized by a time-delayed counter-rotating elliptically polarized laser *** generated vortex-shaped interference pattern in the photoelectron momentum distribution enables us to extract the phase distribution of the electron wave packet in the elliptically polarized laser pulse with high *** artificially screening the ionic potential at different ranges when solving the time-dependent Schördinger equation,we find that the angle-dependent phase distribution of the electron wave packet in the elliptically polarized laser field shows an obvious angular shift as compared to the strong-field approximation,whose value is the same as the attoclock *** also show that the amplitude of the angle-dependent phase distribution is sensitive to the ellipticity of the laser pulse,providing an alternative way to precisely calibrate the laser ellipticity in the attoclock measurement.

关键词： above-threshold ionization photoelectron interference vortex structure

来源：评论

学校读者我要写书评

暂无评论

High Damage Threshold Plasmonic Nanocavity Realized by Single Semiconductor Nanowires for Strong Coupling

引用

The journal of physical chemistry letters 2025年第22期16卷 5579-5585页

作者： Si Kan Xiaobo Han Lin Luo Zijian He Wenjuan Huang Xiaohong Li Huatian Hu Kai Wang Hubei Key Laboratory of Optical Information and Pattern Recognition Wuhan Institute of Technology Wuhan 430205 China. Wuhan National Laboratory for Optoelectronics and School of Physics Huazhong University of Science and Technology Wuhan 430074 China.

Strong coupling, as a unique paradigm of cavity quantum electrodynamics, provides an important foundation for exploring novel quantum phenomena. Under ambient conditions, exciton-plasmon strong coupling systems have developed rapidly with various exquisite nanocavity structures proposed and refined. Nanocavities based on metal nanoparticles, such as single-particle and nanoparticle-on-mirror (NPoM), offer excellent compatibility with exciton materials, making them significant platforms for studying plasmon-exciton strong coupling. However, the intrinsic losses of metallic materials severely limit the exploration of novel quantum phenomena such as low-threshold lasing and nonlinear properties. In this work, we propose and realize a plasmonic nanocavity based on high-refractive-index GaAs nanowires positioned on a Au substrate, forming a nanowire-on-mirror (NWoM) architecture. The NWoM nanocavities exhibit strong local field confinement and a significantly enhanced damage threshold, reaching 5.610 W/cm. Furthermore, by integrating the nanocavity with monolayer WSe, we successfully realized the strong coupling at room temperature. By tuning the diameters of the dielectric nanowires, we observe the characteristic anticrossing behavior and achieve a Rabi splitting of 140 meV. This study lays the foundation for future investigations into more efficient quantum behaviors and provides a new approach to designing low-loss strong coupling systems.

关键词：

来源：评论

学校读者我要写书评

暂无评论

Temporal Goos-Hänchen Shift in Synthetic Discrete-Time Heterolattices

引用

Physical Review Letters 2024年第8期133卷 083802页

作者： Chengzhi Qin Shulin Wang Bing Wang Xinyuan Hu Chenyu Liu Yinglan Li Lange Zhao Han Ye Stefano Longhi Peixiang Lu Wuhan National Laboratory for Optoelectronics and School of Physics Dipartimento di Fisica Instituto de Fisica Interdisciplinar y Sistemas Complejos E-07122 Palma de Mallorca Spain Hubei Key Laboratory of Optical Information and Pattern Recognition

Experimental demonstration of tunable temporal Goos-Hänchen shift (GHS) in synthetic discrete-time heterolattices with scalar and vector gauge potentials is reported. By using Heaviside-function modulation in two fiber loops, we create a sharp gauge-potential interface and observe temporal GHS for total internal reflection (TIR), which manifests as a time delay rather than a spatial shift. The TIR occurs as the incident mode falls into the band gap of transmitted region with band shifting by scalar and vector potential. We find that both scalar and vector potential codetermine GHS by controlling the decay (imaginary part) and oscillation (real part) of a penetrated evanescent wave, in stark contrast to traditional spatial GHS only determined by the decay factor. We also observe diverging characteristics of GHS at band-gap edges where evanescent-to-propagating wave transition occurs. GHS for frustrated total internal reflection (FTIR) by a finite-width evanescent barrier is also demonstrated, which shows saturation properties to the single-interface TIR case under infinite-width limit. Finally, we develop an accumulation measurement method using multiple TIRs to improve the precision for measuring even tinier GHS. The study initiates precise measurement of temporal GHS for discrete-time reflections, which may feature potential applications in precise time-delay control and measurement.

关键词： Evanescent waves Geometrical & wave optics Refraction Synthetic gauge fields Topological effects in photonic systems Lattices optical fibers

来源：评论

学校读者我要写书评

暂无评论

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案：

请选择收藏分类：

通借通还

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：