期刊文献+
共找到15篇文章
< 1 >
每页显示 20 50 100
Convolutional neural network for transient grating frequency-resolved optical gating trace retrieval and its algorithm optimization 被引量:1
1
作者 Siyuan Xu Xiaoxian Zhu +7 位作者 Ji Wang Yuanfeng Li Yitan Gao Kun Zhao Jiangfeng Zhu Dacheng Zhang Yunlin Chen Zhiyi Wei 《Chinese Physics B》 SCIE EI CAS CSCD 2021年第4期586-590,共5页
A convolutional neural network is employed to retrieve the time-domain envelop and phase of few-cycle femtosecond pulses from transient-grating frequency-resolved optical gating(TG-FROG) traces.We use theoretically ge... A convolutional neural network is employed to retrieve the time-domain envelop and phase of few-cycle femtosecond pulses from transient-grating frequency-resolved optical gating(TG-FROG) traces.We use theoretically generated TGFROG traces to complete supervised trainings of the convolutional neural networks,then use similarly generated traces not included in the training dataset to test how well the networks are trained.Accurate retrieval of such traces by the neural network is realized.In our case,we find that networks with exponential linear unit(ELU) activation function perform better than those with leaky rectified linear unit(LRELU) and scaled exponential linear unit(SELU).Finally,the issues that need to be addressed for the retrieval of experimental data by this method are discussed. 展开更多
关键词 transient-grating frequency-resolved optical gating convolutional neural network activation function phase retrieval algorithm
下载PDF
Tuning of the Electron Spin Relaxation Anisotropy via Optical Gating in GaAs/AlGaAs Quantum Wells
2
作者 牛秉慧 闫腾飞 +2 位作者 倪海桥 牛智川 张新惠 《Chinese Physics Letters》 SCIE CAS CSCD 2016年第10期120-123,共4页
The carrier-density-dependent spin relaxation dynamics for modulation-doped GaAs/Al0.3 Gao,TAs quantum wells is studied using the time-resolved magneto-Kerr rotation measurements. The electron spin relaxation time and... The carrier-density-dependent spin relaxation dynamics for modulation-doped GaAs/Al0.3 Gao,TAs quantum wells is studied using the time-resolved magneto-Kerr rotation measurements. The electron spin relaxation time and its in-plane anisotropy are studied as a function of the optically injected electron density, Moreover, the relative strength of the Rashba and the Dresselhaus spin-rbit coupling fields, and thus the observed spin relaxation time anisotropy, is further tuned by the additional excitation of a 532nm continuous wave laser, demonstrating an effective spin relaxation manipulation via an optical gating method. 展开更多
关键词 GAAS on is Tuning of the Electron Spin Relaxation Anisotropy via optical gating in GaAs/AlGaAs Quantum Wells of in
下载PDF
Wavelength-dependence of double optical gating for attosecond pulse generation
3
作者 田佳 黎敏 +2 位作者 于济洲 邓勇开 刘运全 《Chinese Physics B》 SCIE EI CAS CSCD 2014年第10期175-179,共5页
Both polarization gating (PG) and double optical gating (DOG) are productive methods to generate single attosecond (as) pulses. In this paper, considering the ground-state depletion effect, we investigate the wa... Both polarization gating (PG) and double optical gating (DOG) are productive methods to generate single attosecond (as) pulses. In this paper, considering the ground-state depletion effect, we investigate the wavelength-dependence of the DOG method in order to optimize the generation of single attosecond pulses for the future application. By calculating the ionization probabilities of the leading edge of the pulse at different driving laser wavelengths, we obtain the upper limit of duration for the driving laser pulse for the DOG setup. We find that the upper limit duration increases with the increase of laser wavelength. We further describe the technical method of choosing and calculating the thickness values of optical components for the DOG setup. 展开更多
关键词 double optical gating isolated attosecond pulse ionization probability
下载PDF
Cross-correlation frequency-resolved optical gating scheme based on a periodically poled lithium niobate waveguide for an optical arbitrary waveform measurement
4
作者 Chenwenji WANG Peili LI +3 位作者 Yuying GAN Di CAO Xiaozheng QIAO Chen HE 《Frontiers of Optoelectronics》 EI CSCD 2017年第1期70-79,共10页
This study proposes a novel scheme of a cross- correlation frequency-resolved optical gating (X-FROG) measurement for an optical based on the sum frequency arbitrary waveform (OAW) generation (SFG) effect of a p... This study proposes a novel scheme of a cross- correlation frequency-resolved optical gating (X-FROG) measurement for an optical based on the sum frequency arbitrary waveform (OAW) generation (SFG) effect of a periodically poled lithium niobate (PPLN) waveguide. Based on the SFG effect and combined with the principal component generalized projects algorithm on a matrix, the theory model of the scheme is established. Using Matlab, the proposed OAW measurement X-FROG scheme using the PPLN waveguide is simulated and studied. Simulation results show that a rectangular pulse is a suitable gate pulse because of its low errors. Moreover, the increased complexity of OAW and phase mismatch decrease measurement accuracy. 展开更多
关键词 optical arbitrary waveform (0AW) measure-ment periodically poled lithium niobate (PPLN) cross-correlation frequency-resolved optical gating (X-FROG)
原文传递
Advanced optical microscopy methods for in vivo imaging of sub-cellular structures in thick biological tissuesl
5
作者 Nanguang Chen Shakil Rehman Colin J.R.Sheppard 《Journal of Innovative Optical Health Sciences》 SCIE EI CAS 2014年第5期64-90,共27页
Optical microscopy has become an indispensable tool for visualizing sub-cellular structures andbiological processes.However,scattering in biological tissues is a major obstacle that preventshigh-resolution images from... Optical microscopy has become an indispensable tool for visualizing sub-cellular structures andbiological processes.However,scattering in biological tissues is a major obstacle that preventshigh-resolution images from being obtained from deep regions of tissue.We review commontechniques,such as multiphoton microscopy(MPM)and optical coherence microscopy(OCM),for diffraction limited imaging beyond an imaging depth of 0.5 mm.Novel implementations havebeen emerging in recent years giving higher imaging speed,deeper penetration,and better imagequality.Focal modulation microscopy(FMM)is a novel method that combines confocal spatialfltering with focal modulation to reject out-of-focus background.FMM has demonstrated animaging depth comparable to those of MPM and OCM,near-real-time image acquisition,and thecapability for multiple contrast mechanisms. 展开更多
关键词 Confocal microscopy multiphoton microscopy(MPM) optical gating optical coherence tomography(OCT) optical coherence microscopy(OCM) focal modulation microscopy(FMM).
下载PDF
Wide-Band Polarization-Independent Semiconductor Optical Amplifier Gate with Tensile-Strained Quasi-Bulk InGaAs
6
作者 王书荣 刘志宏 +6 位作者 王圩 朱洪亮 张瑞英 丁颖 赵玲娟 周帆 王鲁峰 《Journal of Semiconductors》 EI CAS CSCD 北大核心 2004年第8期898-902,共5页
A semiconductor optical amplifier gate based on tensile strained quasi bulk InGaAs is developed.At injection current of 80mA,a 3dB optical bandwidth of more than 85nm is achieved due to dominant band filling effect... A semiconductor optical amplifier gate based on tensile strained quasi bulk InGaAs is developed.At injection current of 80mA,a 3dB optical bandwidth of more than 85nm is achieved due to dominant band filling effect.Moreover,the most important is that very low polarization dependence of gain (<0 7dB),fiber to fiber lossless operation current (70~90mA) and a high extinction ratio (>50dB) are simultaneously obtained over this wide 3dB optical bandwidth (1520~1609nm) which nearly covers the spectral region of the whole C band (1525~1565nm) and the whole L band (1570~1610nm).The gating time is also improved by decreasing carrier lifetime.The wide band polarization insensitive SOA gate is promising for use in future dense wavelength division multiplexing (DWDM) communication systems. 展开更多
关键词 semiconductor optical amplifier gate wide bandwidth polarization insensitive tensile strained quasi bulk InGaAs fiber to fiber lossless operation current extinction ratio
下载PDF
Imaging Transparent Objects in a Turbid Medium Using a Femtosecond Optical Kerr Gate 被引量:1
7
作者 Yi-Peng Zheng Jin-Hai Si +3 位作者 Wen-Jiang Tan Xiao-Jing Liu Jun-Yi Tong Xun Hou 《Chinese Physics Letters》 SCIE CAS CSCD 2017年第10期49-51,共3页
A femtosecond optical Kerr gate time-gated ballistic imaging method is demonstrated to image a transparent object in a turbid medium. The shape features of the object are obtained by time-resolved selection of the bal... A femtosecond optical Kerr gate time-gated ballistic imaging method is demonstrated to image a transparent object in a turbid medium. The shape features of the object are obtained by time-resolved selection of the ballistic photons with different optical path lengths, the thickness distribution of the object is mapped, and the maximum is less than 3.6%. This time-resolved ballistic imaging has potential applications in studying properties of the liquid core in the near field of the fuel spray. 展开更多
关键词 Imaging Transparent Objects in a Turbid Medium Using a Femtosecond optical Kerr Gate
下载PDF
High contrast all-optical diode based on direction-dependent optical bistability within asymmetric ring cavity
8
作者 夏秀文 张新琴 +1 位作者 许静平 羊亚平 《Chinese Physics B》 SCIE EI CAS CSCD 2016年第8期206-210,共5页
We propose a simple all-optical diode which is comprised of an asymmetric ring cavity containing a two-level atomic ensemble. Attributed to spatial symmetry breaking of the ring cavity, direction-dependent optical bis... We propose a simple all-optical diode which is comprised of an asymmetric ring cavity containing a two-level atomic ensemble. Attributed to spatial symmetry breaking of the ring cavity, direction-dependent optical bistability is obtained in a classical bistable system. Therefore, a giant optical non-reciprocity is generated, which guarantees an all-optical diode with a high contrast up to 22 d B. Furthermore, its application as an all-optical logic AND gate is also discussed. 展开更多
关键词 optical diode optical bistability optical logic gate
下载PDF
The study of numerical character for femtosecond pulse shaping 被引量:2
9
作者 邹华 朱卫华 王国栋 《Chinese Physics B》 SCIE EI CAS CSCD 2007年第11期3429-3433,共5页
This paper describes the generation of shaped femtosecond multiple pulses by using the phase-only Dammann filters in 4f femtosecond shaper and gives the experimental result of femtosecond pulse characterization by the... This paper describes the generation of shaped femtosecond multiple pulses by using the phase-only Dammann filters in 4f femtosecond shaper and gives the experimental result of femtosecond pulse characterization by the frequency- resolved optical gating (FROG) technique. With the theoretical simulation, it concludes that the quality of the generated output array is relevant to the number of pixels and the spacing between the components. 展开更多
关键词 space-time conversion femtosecond pulse shaping Dammann frequency-resolved optical gating
下载PDF
Experimental determination of effective light transport properties in fully anisotropic media
10
作者 Ernesto Pini Peter Naglic +4 位作者 Miran Bürmen Alexander Gatto Henrik Schäfer Diederik S.Wiersma Lorenzo Pattelli 《Advanced Photonics Nexus》 2024年第5期174-181,共8页
Structurally anisotropic materials are ubiquitous in several application fields,yet their accurate optical characterization remains challenging due to the lack of general models linking their scattering coefficients t... Structurally anisotropic materials are ubiquitous in several application fields,yet their accurate optical characterization remains challenging due to the lack of general models linking their scattering coefficients to the macroscopic transport observables and the need to combine multiple measurements to retrieve their direction-dependent values.Here,we present an improved method for the experimental determination of light-transport tensor coefficients from the diffusive rates measured along all three directions,based on transient transmittance measurements and a generalized Monte Carlo model.We apply our method to the characterization of light-transport properties in two common anisotropic materials—polytetrafluoroethylene tape and paper—highlighting the magnitude of systematic deviations that are typically incurred when neglecting anisotropy. 展开更多
关键词 multiple scattering time-resolved transmittance anisotropic diffusion scattering tensor optical gating fibrous materials
下载PDF
Photonic crystal cavities and integrated optical devices 被引量:2
11
作者 GAN Lin LI ZhiYuan 《Science China(Physics,Mechanics & Astronomy)》 SCIE EI CAS CSCD 2015年第11期11-22,共12页
This paper gives a brief introduction to our recent works on photonic crystal(Ph C) cavities and related integrated optical structures and devices. Theoretical background and numerical methods for simulation of Ph C c... This paper gives a brief introduction to our recent works on photonic crystal(Ph C) cavities and related integrated optical structures and devices. Theoretical background and numerical methods for simulation of Ph C cavities are first presented. Based on the theoretical basis, two relevant quantities, the cavity mode volume and the quality factor are discussed. Then the methods of fabrication and characterization of silicon Ph C slab cavities are introduced. Several types of Ph C cavities are presented, such as the usual L3 missing-hole cavity, the new concept waveguide-like parallel-hetero cavity, and the low-index nanobeam cavity. The advantages and disadvantages of each type of cavity are discussed. This will help the readers to decide which type of Ph C cavities to use in particular applications. Furthermore, several integrated optical devices based on Ph C cavities, such as optical filters, channel-drop filters, optical switches, and optical logic gates are described in both the working principle and operation characteristics. These devices designed and realized in our group demonstrate the wide range of applications of Ph C cavities and offer possible solutions to some integrated optical problems. 展开更多
关键词 photonic crystal cavities optical filter optical switch optical logic gates
原文传递
All-optical AND/OR/NOT logic gates based on photonic crystal ring resonators 被引量:2
12
作者 Ashkan PASHAMEHR Mahdi ZAVVARI Hamed ALIPOUR-BANAEI 《Frontiers of Optoelectronics》 EI CSCD 2016年第4期578-584,共7页
Photonic crystal based ring resonators are best choice for designing all-optical devices. In this paper, we used a basic structure of photonic crystal ring resonators and designed all optical logic gates which are wor... Photonic crystal based ring resonators are best choice for designing all-optical devices. In this paper, we used a basic structure of photonic crystal ring resonators and designed all optical logic gates which are working using the Kerr effect. The proposed gates consisted of upper and lower wavegnides coupled through a resonator which was designed for dropping of special wavelength. The resonance wavelength was designed for 1550 nm telecom operation wavelength. We used numerical meth- ods such as plane wave expansion and finite difference time domain (FDTD) for performing our simulations and studied the optical properties of the proposed structures. Our results showed that the critical input power for triggering the gate output was lower compared to previously reported gates. 展开更多
关键词 photonic crystal (PhC) all optical logic gate ring resonator Kerr effect
原文传递
QKD system with fast active optical path length compensation
13
作者 Byung Kwon Park Min Soo Lee +3 位作者 Min Ki Woo Yong-Su Kim Sang-Wook Han Sung Moon 《Science China(Physics,Mechanics & Astronomy)》 SCIE EI CAS CSCD 2017年第6期1-7,共7页
We develop a quantum key distribution (QKD) system with fast active optical path length compensation. A rapid and reliable active optical path length compensation scheme is proposed and applied to a plug-and-play QKD ... We develop a quantum key distribution (QKD) system with fast active optical path length compensation. A rapid and reliable active optical path length compensation scheme is proposed and applied to a plug-and-play QKD system. The system monitors changes in key rates and controls it is own operation automatically. The system achieves its optimal performance within three seconds of operation, which includes a sifted key rate of 5.5 kbps and a quantum bit error rate of less than 2% after an abrupt temperature variation along the 25 km quantum channel. The system also operates well over a 24 h period while completing more than 60 active optical path length compensations. 展开更多
关键词 quantum key distribution optical path length compensation plug and play field programmable gate array
原文传递
Atomically-precise Au_(24)Ag_(1) Clusterzymes with Enhanced Peroxidase-like Activity for Bioanalysis
14
作者 WANG Shuna LI Zhe +5 位作者 XIA Mingyuan ZHAO Xiaoxue CHEN Chuanxia JIANG Yuanyuan NI Pengjuan LU Yizhong 《Chemical Research in Chinese Universities》 SCIE CAS CSCD 2023年第6期907-914,共8页
Atomically-precise clusterzymes have been widely studied for their special physicochemical properties,but it is still a challenge to enhance their peroxidase-like activity.Herein,we demonstrated that by substituting a... Atomically-precise clusterzymes have been widely studied for their special physicochemical properties,but it is still a challenge to enhance their peroxidase-like activity.Herein,we demonstrated that by substituting a single Ag atom into Au25 nanoclusters to form Au_(24)Ag_(1) nanoclusters,the peroxidase-like activity was enhanced greatly.In the presence of H_(2)O_(2),Au_(24)Ag_(1) could produce reactive oxygen species(ROS)to oxidize colorless 3,3'5,5'-tetramethylbenzidine(TMB)to the blue oxidized TMB(oxTMB).It is worth mentioning that pyrophosphate compounds inhibit the activity of Au_(24)Ag_(1).Since alkaline phosphatase(ALP)can dephosphorylate the substrate phosphate compound,that is,remove the phosphate group on the substrate by hydrolysis,the enzymatic activity of the clusterzyme is restored.Based on this,we have developed a sensitive and reliable colorimetric sensing system for the detection of pyrophosphate ion(PPi),adenosine triphosphate(ATP),adenosine diphosphate(ADP)and ALP,respectively.Importantly,the detection limit of the assay system is lower than those of most of the assays that have been reported.In addition,we also built a simple optical logic gate on this basis,further extending the application of metal nanoclusters as peroxidase mimics in bioanalysis.This work could help to shed light on the structure-activity relationship of nanozyme. 展开更多
关键词 NANOCLUSTER Atom manipulation Nanozyme Bioanaly-sis optical logic gate
原文传递
Spatio-temporal visualization of light transport in complex photonic structures
15
作者 Lorenzo Pattelli Romolo Savo +1 位作者 Matteo Burresi Diederik S Wiersma 《Light(Science & Applications)》 SCIE EI CAS CSCD 2016年第1期714-722,共9页
Spatio-temporal imaging of light propagation is very important in photonics because it provides the most direct tool available to study the interaction between light and its host environment.Sub-ps time resolution is ... Spatio-temporal imaging of light propagation is very important in photonics because it provides the most direct tool available to study the interaction between light and its host environment.Sub-ps time resolution is needed to investigate the fine and complex structural features that characterize disordered and heterogeneous structures,which are responsible for a rich array of transport physics that have not yet been fully explored.A newly developed wide-field imaging system enables us to present a spatiotemporal study on light transport in various disordered media,revealing properties that could not be properly assessed using standard techniques.By extending our investigation to an almost transparent membrane,a configuration that has been difficult to characterize until now,we unveil the peculiar physics exhibited by such thin scattering systems with transport features that go beyond mainstream diffusion modeling,despite the occurrence of multiple scattering. 展开更多
关键词 diffusive approximation disordered media light transport optical gating wide-field imaging
原文传递
上一页 1 下一页 到第
使用帮助 返回顶部