检索结果-内蒙古大学图书馆

Negative Refraction Achieved by Inducing Chirality in Monolayer Graphene Through Raman Gain Mechanism

学校读者我要写书评

暂无评论

SSRN

SSRN 2023年

作者： Abbas, Muqaddar Badshah, Fazal Zhou, Yuan Ullah, Rahmat He, Qing School of Electrical and Information Engineering Hubei University of Automotive Technology Shiyan442002 China Ministry of Education Key Laboratory for Nonequilibrium Synthesis and Modulation of Condensed Matter Shaanxi Province Key Laboratory of Quantum Information and Quantum Optoelectronic Devices School of Physics Xi’an Jiaotong University Xi’an710049 China School of Mathematics Physics and Optoelectronics Engineering Hubei University of Automotive Technology Shiyan442002 China Quantum optics Lab Department of Physics COMSATS University Islamabad Islamabad Pakistan College of Science Zhongyuan University of Technology Zhongyuan Road Zhengzhou450000 China Hubei Key Laboratory of Optical Information and Pattern Recognition Wuhan Institute of Technology Wuhan430205 China

We investigate negative refraction directed by chirality under the condition of Raman gain process in Landau level of graphene. The coupling of magnetic dipole transition with an electric dipole transition leads to Raman gain induced chirality and observe negative refraction with positive permeability. The key idea of our system is to avoid absorption and get negative refraction without the need of simultaneous negative permittivity and permeability. We establish that negative index for refraction may be achieved with minimal absorption by using magnetoelectric cross-coupling to couple two mutually interfering Raman transitions via magnetic-dipole transition. Further, we examine the negative refraction via Doppler-broadened medium. Our proposed scheme may use to develop perfect lenses made from negative index materials that may provide a novel technique to resolve nanoscale objects, with far-reaching practical consequences. © 2023, The Authors. All rights reserved.

关键词： Graphene

Attention in Attention: Modeling Context Correlation for Efficient Video Classification

学校读者我要写书评

暂无评论

arXiv 2022年

作者： Hao, Yanbin Wang, Shuo Cao, Pei Gao, Xinjian Xu, Tong Wu, Jinmeng He, Xiangnan The CCCD Key Lab of Ministry of Culture and Tourism School of Data Science School of Information Science and Technology University of Science and Technology of China Anhui 230026 China The Wuhan Research Institute of Posts and Telecommunications Hubei Wuhan430205 China The School of Computer Science and Information Engineering School of Artificial Intelligence Hefei University of Technology Anhui 230009 China The School of Data Science School of Computer Science and Technology University of Science and Technology of China Anhui 230026 China The Hubei Key Laboratory of Optical Information and Pattern Recognition Wuhan Institute of Technology Hubei Wuhan430070 China

Attention mechanisms have significantly boosted the performance of video classification neural networks thanks to the utilization of perspective contexts. However, the current research on video attention generally focuses on adopting a specific aspect of contexts (e.g., channel, spatial/temporal, or global context) to refine the features and neglects their underlying correlation when computing attentions. This leads to incomplete context utilization and hence bears the weakness of limited performance improvement. To tackle the problem, this paper proposes an efficient attention-in-attention (AIA) method for element-wise feature refinement, which investigates the feasibility of inserting the channel context into the spatio-temporal attention learning module, referred to as CinST, and also its reverse variant, referred to as STinC. Specifically, we instantiate the video feature contexts as dynamics aggregated along a specific axis with global average and max pooling operations. The workflow of an AIA module is that the first attention block uses one kind of context information to guide the gating weights calculation of the second attention that targets at the other context. Moreover, all the computational operations in attention units act on the pooled dimension, which results in quite few computational cost increase ( Copyright © 2022, The Authors. All rights reserved.

关键词： Machine learning

Spectrally uncorrelated biphotons generated from "the family of BBO crystal"

学校读者我要写书评

暂无评论

Quantum Engineering

Quantum Engineering 2020年第2期2卷

作者： Jin, Rui-Bo Cai, Wu-Hao Ding, Chunling Mei, Feng Deng, Guang-Wei Shimizu, Ryosuke Zhou, Qiang Hubei Key Laboratory of Optical Information and Pattern Recognition Wuhan Institute of Technology Wuhan China State Key Laboratory of Quantum Optics and Quantum Optics Devices Institute of Laser Spectroscopy Shanxi University Taiyuan China Collaborative Innovation Center of Extreme Optics Shanxi University Taiyuan China Institute of Fundamental and Frontier Sciences and School of Optoelectronic Science and Engineering University of Electronic Science and Technology of China Chengdu China CAS Key Laboratory of Quantum Information University of Science and Technology of China Hefei China The University of Electro-Communications Chofu Japan

Spectrally intrinsically uncorrelated biphoton states generated from nonlinear crystals are very important but rare resources for quantum photonics and quantum information applications. Previously, such biphoton states were generated from several kinds of crystals, however, their wavelength ranges and nonlinear efficiencies were still limited for various applications. In order to explore new crystal for wider wavelength range and higher nonlinear efficiency, here we theoretically study the generation of spectrally uncorrelated biphoton states from 14 crystals in the "BBO family," including BBO, CLBO, KABO, KBBF, RBBF, CBBF, BABF, BiBO, LBO, CBO, LRB4, LCB, YCOB, and GdCOB. They satisfy three kinds of group-velocity matching condition from near-infrared to telecom wavelengths. Furthermore, heralded single photons can be generated with a purity as high as 0.98, which is achieved without any narrow filtering. The indistinguishability of photons from independent sources is examined by the Hong-Ou-Mandel interference, which results in a visibility of 98% also without any further filtering, that is, photons from different heralded single-photon sources are highly indistinguishable. Our study may provide single-photon sources with good performance for quantum information processing at near-infrared and telecom wavelengths. © 2020 John Wiley & Sons, Ltd.

关键词： Photons

A High-Frequency Sound based PGC Demodulation Scheme for Fiber Optics Hydrophone

学校读者我要写书评

暂无评论

Research Square

Research Square 2021年

作者： Shi, Yunjie Yin, Mengke Zhu, Zijue Wang, Shun Niu, Panting Dong, Yuming Zhang, Liang Shenzhen Institutes of Advanced Technology Chinese Academy of Sciences Shenzhen518055 China School of Civil and Environmental Engineering Nanyang Technological University 50 Nanyang Avenue 639798 Singapore Hubei Key Laboratory of Optical Information and Pattern Recognition Wuhan Institute of Technology Wuhan430205 China Schools of Science Changchun University of Science and Technology Changchun130022 China

In the research field of fiber-optic hydrophone, the performance of demodulation scheme is crucial. In this work, a phase-generated-carrier (PGC) demodulation scheme based on high-frequency sound source is proposed. High-frequency acoustic signal from the external sound source is applied to the fiber-optic hydrophone to achieve phase modulation of the interference signal instead of the piezo-electrical transducer (PZT) or frequency-modulated laser. It possesses the merits of low system complexity and low cost. Through the acoustic detection experiment, we achieve demodulation of acoustic signal at frequency varying from 300 Hz to 800 Hz, and the signal-to-noise ratio (SNR) is higher than 45 dB. Furthermore, the proposed scheme is successfully applied to time division multiplexing (TDM) experiment. © 2021, CC BY.

关键词： Phase modulation

Mid-infrared spectrally-uncorrelated biphotons generation from doped PPLN: A theoretical investigation

学校读者我要写书评

暂无评论

arXiv 2020年

作者： Wei, Bei Cai, Wu-Hao Ding, Chunling Deng, Guang-Wei Shimizu, Ryosuke Zhou, Qiang Jin, Rui-Bo Hubei Key Laboratory of Optical Information and Pattern Recognition Wuhan Institute of Technology Wuhan430205 China Institute of Fundamental and Frontier Sciences School of Optoelectronic Science and Engineering University of Electronic Science and Technology of China Chengdu610054 China CAS Key Laboratory of Quantum Information University of Science and Technology of China Hefei230026 China University of Electro-Communications 1-5-1 Chofugaoka Chofu Tokyo Japan State Key Laboratory of Quantum Optics and Quantum Optics Devices Shanxi University Taiyuan030006 China

We theoretically investigate the preparation of mid-infrared (MIR) spectrally-uncorrelated biphotons from a spontaneous parametric down-conversion process using doped LN crystals, including MgO doped LN, ZnO doped LN, and In2O3 doped ZnLN with doping ratio from 0 to 7 mol%. The tilt angle of the phase-matching function and the corresponding poling period are calculated under type-II, type-I, and type-0 phase-matching conditions. We also calculate the thermal properties of the doped LN crystals and their performance in Hong-Ou-Mandel interference. It is found that the doping ratio has a substantial impact on the group-velocity-matching (GVM) wavelengths. Especially, the GVM2 wavelength of co-doped InZnLN crystal has a tunable range of 678.7 nm, which is much broader than the tunable range of less than 100 nm achieved by the conventional method of adjusting the temperature. It can be concluded that the doping ratio can be utilized as a degree of freedom to manipulate the biphoton state. The spectrally uncorrelated biphotons can be used to prepare pure single-photon source and entangled photon source, which may have promising applications for quantum-enhanced sensing, imaging, and communications at the MIR range. Copyright © 2020, The Authors. All rights reserved.

关键词： Infrared devices

Optimized design of the lithium niobate for spectrally-pure-state generation at MIR wavelengths using metaheuristic algorithm

学校读者我要写书评

暂无评论

arXiv 2022年

作者： Cai, Wu-Hao Tian, Ying Wang, Shun You, Chenglong Zhou, Qiang Jin, Rui-Bo Hubei Key Laboratory of Optical Information and Pattern Recognition Wuhan Institute of Technology Wuhan430205 China Quantum Photonics Laboratory Department of Physics and Astronomy Louisiana State University Baton RougeLA70803 United States Institute of Fundamental and Frontier Sciences School of Optoelectronic Science and Engineering University of Electronic Science and Technology of China Chengdu610054 China Guangdong Provincial Key Laboratory of Quantum Science and Engineering Southern University of Science and Technology Shenzhen518055 China

Quantum light sources in the mid-infrared (MIR) band play an important role in many applications, such as quantum sensing, quantum imaging, and quantum communication. However, there is still a lack of high-quality quantum light sources in the MIR band, such as the spectrally pure single-photon source. In this work, we present the generation of spectrally-pure state in an optimized poled lithium niobate crystal using a metaheuristic algorithm. In particular, we adopt the particle swarm optimization algorithm to optimize the duty cycle of the poling period of the lithium niobate crystal. With our approach, the spectral purity can be improved from 0.820 to 0.998 under the third group-velocity-matched condition, and the wavelength-tunable range is from 3.0 µm to 4.0 µm for the degenerate case and 3.0 µm to 3.7 µm for the nondegenerate case. Our work paves the way for developing quantum photonic technologies at the MIR wavelength band. © 2022, CC BY.

关键词： Lithium

The Investigation of Terahertz Metamaterials by Normalized Power Transmission

学校读者我要写书评

暂无评论

The Investigation of Terahertz Metamaterials by Normalized P...

2012 3rd International Conference on Applied Mechanics and Mechanical Engineering(ICAMME 2012)

作者： Jun Luo Ying Chen Shengwu Kang Xinyu Zhang Changsheng Xie Tianxu Zhang Institute for Pattern Recognition & Artificial Intelligence Huazhong University of Science & Technology College of Sciences Huazhong Agricultural University Hubei Province Fiber Inspection Bureau Wuhan National Laboratory for Optoelectronics Huazhong University of Science & Technology National Key Laboratory of Science & Technology on Multispectral Information Processing Huazhong University of Science & Technology

We present the design and fabrication of metamaterials, and investigated the normalized power transmission properties of four metamaterials at different frequency in terahertz regime. We compared the power transmissio... 详细信息

关键词： Metamaterials Terahertz Normalized Transmission Power

Octave-spanning supercontinuum coherent soft X-ray for producing a single-cycle soft X-ray pulse

学校读者我要写书评

暂无评论

arXiv 2024年

作者： Nishimiya, Kaito Wang, Feng Lan, Pengfei Takahashi, Eiji J. Ultrafast Coherent Soft X-ray Photonics Research Team RIKEN Center for Advanced Photonics RIKEN Wako Japan Extreme Laser Science Laboratory RIKEN Cluster for Pioneering Research RIKEN Wako Japan Hubei Key Laboratory of Optical Information and Pattern Recognition Wuhan Institute of Technology Wuhan430205 China Wuhan National Laboratory for Optoelectronics School of Physics Huazhong University of Science and Technology Wuhan430074 China

This study demonstrates the potential to generate a soft X-ray single-cycle attosecond pulse using a single-cycle midinfrared pulse from advanced dual-chirped optical parametric amplification. A super continuum high harmonic (HH) spectrum was generated in argon (80 eV–160 eV) and neon (150 eV–270 eV). The experimental spectra reasonably agree with those calculated by the strong-field approximation model and Maxwell’s equations. In addition, simulation results indicate that the dispersion of HHs in argon can be compensated using a 207-nm Zr filter to obtain 40 as pulses (1.1 cycles at 118 eV). For neon, a 278-nm Sn filter can compensate for dispersion of HH and create 23 as pulses (1.1 cycles at 206 eV). This soft X-ray single-cycle attosecond pulse is expected to be highly valuable for ultrafast science and applications in quantum information science. Copyright © 2024, The Authors. All rights reserved.

关键词： Maxwell equations

High-quality multi-wavelength quantum light sources on silicon nitride micro-ring chip

学校读者我要写书评

暂无评论

arXiv 2022年

作者： Fan, Yun-Ru Lyu, Chen Yuan, Chen-Zhi Deng, Guang-Wei Zhou, Zhi-Yuan Geng, Yong Song, Hai-Zhi Wang, You Zhang, Yan-Feng Jin, Rui-Bo Zhou, Heng You, Li-Xing Guo, Guang-Can Zhou, Qiang Institute of Fundamental and Frontier Sciences University of Electronic Science and Technology of China Chengdu610054 China CAS Key Laboratory of Quantum Information University of Science and Technology of China Hefei230026 China Key Lab of Optical Fiber Sensing and Communication Networks University of Electronic Science and Technology of China Chengdu611731 China Southwest Institute of Technical Physics Chengdu610041 China School of Electronics and Information Technology Sun Yat-sen University Guangzhou510275 China Hubei Key Laboratory of Optical Information and Pattern Recognition Wuhan Institute of Technology Wuhan430205 China Shanghai Institute of Microsystem and Information Technology Chinese Academy of Sciences Shanghai200050 China

Multi-wavelength quantum light sources, especially at telecom band, are extremely desired in quantum information technology. Despite recent impressive advances, such a quantum light source with high quality remains challenging. Here we demonstrate a multi-wavelength quantum light source using a silicon nitride micro-ring with a free spectral range of 200 GHz. The generation of eight pairs of correlated photons is ensured in a wavelength range of 25.6 nm. With device optimization and noise-rejecting filters, our source enables the generation of heralded single-photons - at a rate of 62 kHz with gh(2)(0) = 0.014 ± 0.001, and the generation of energy-time entangled photons - with a visibility of 99.39 ± 0.45% in the Franson interferometer. These results, at room temperature and telecom wavelength, in a CMOS compatible platform, represent an important step towards integrated quantum light devices for the quantum networks. Copyright © 2022, The Authors. All rights reserved.

关键词： Light sources