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Deep-subwavelength single grooves prepared by femtosecond laser direct writing on Si

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Chinese Physics B 2024年第8期33卷 108-115页

作者：叶瑞熙黄敏 State Key Laboratory of Optoelectronic Materials and Technologies School of PhysicsSun Yat-sen UniversityGuangzhou 510275China

It is well known that femtosecond laser pulses can easily spontaneously induce deep-subwavelength periodic surface structures on transparent dielectrics but not on non-transparent ***,in this study,we demonstrate that using high-numerical-aperture 800 nm femtosecond laser direct writing with controlled pulse energy and scanning speed in the near-damage-threshold regime,polarization-dependent deep-subwavelength single grooves with linewidths of~180 nm can be controllably prepared on ***,the single-groove linewidth increases slightly with increase in the pulse energy and decrease in the scanning speed,whereas the single-groove depth significantly increases from~300 nm to~600 nm with decrease in the scanning speed,or even to over 1μm with multi-processing,indicating the characteristics of transverse clamping and longitudinal growth of such deep-subwavelength single *** dispersive spectroscopy composition analysis of the near-groove region confirms that single-groove formation tends to be an ultrafast,non-thermal ablation process,and the oxidized deposits near the grooves are easy to clean ***,the results,showing both the strong dependence of groove orientation on laser polarization and the occurrence of double-groove structures due to the interference of pre-formed orthogonal grooves,indicate that the extraordinary field enhancement of strong polarization sensitivity in the deep-subwavelength groove plays an important role in single-groove growth with high stability and collimation.

关键词： femtosecond-laser direct writing of Si deep-subwavelength single grooves polarization dependence high numerical aperture ultrafast non-thermal ablation

Simultaneous Strain and Temperature Measurement with Optical Fiber Gratings: Error Analysis

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Chinese Journal of Lasers 2000年第3期9卷 52-57页

作者： JIA Hongzhi LI Yulin (xi’an institute of optics & {2. mechanics, The Chinese Academy of Sciences, xi’an 710068, china) 中科院西安光学精密机械所陕西西安

Many schemes designed to simultaneously measure strain and t emperature with optical fiber grating sensors have been reported in recent years. In this paper, the influence of systematic errors associated with the measurement process is analyzed and the error formulas are derived. The results are applied to a range of techniques that are of current interest in the literature. The performance of these schemes is contrasted with respect to the influence of wavelength measurement error and sensitivity matrix error.

关键词： fiber grating sensors strain measurement temperature measurement error analysis

A complex variable meshless method for fracture problems

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Science china(Physics,mechanics & Astronomy) 2006年第1期49卷 46-59页

作者： CHENG Yumin1 & LI Jiuhong2.1. Shanghai institute of Applied Mathematics and mechanics, Shanghai University, Shanghai 2.0072.{2. 2. Department of Building Engineering, xi’an University of Technology, xi’an 710048,{2. Shanghai institute of Applied Mathematics and mechanics Shanghai University Shanghai China Department of Building Engineering Xi’an University of Technology Xi’an China

Based on the moving least-square (MLS) approximation, the complex variable moving least-square approximation (CVMLS) is discussed in this paper. The complex variable moving least-square approximation cannot form ill-conditioned equations, and has greater precision and computational efficiency. Using the analytical solution near the tip of a crack, the trial functions in the complex variable moving least-square approxi- mation are extended, and the corresponding approximation function is obtained. And from the minimum potential energy principle, a complex variable meshless method for fracture problems is presented, and the formulae of the complex variable meshless method are obtained. The complex variable meshless method in this paper has greater precision and computational efficiency than the conventional meshless method. Some examples are given.

关键词： moving least-square approximation, complex variable moving least-square approximation, meshless method, complex variable meshless method, fracture.

Studies　on　Passive　Mode－Locking　Characteristics　of　Nd：YAG　Laser　With　a　Nonlinear　Coupled－Cavity

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Chinese Journal of Lasers 1995年第1期B4卷 19-24页

作者： CHENG Zhao XU Dalun(State Key Laboratory of Transient optics and Technology,xi an institute of optics and precision mechanics,Academia Sinica,xi,an 710068, china) xi'an Inst of optics and precision Mechanics Xi'an China

ＳｔｕｄｉｅｓｏｎＰａｓｓｉｖｅＭｏｄｅ－ＬｏｃｋｉｎｇＣｈａｒａｃｔｅｒｉｓｔｉｃｓｏｆＮｄ：ＹＡＧＬａｓｅｒＷｉｔｈａＮｏｎｌｉｎｅａｒＣｏｕｐｌｅｄ－ＣａｖｉｔｙＳｔｕｄｉｅｓｏｎＰａｓｓｉｖｅＭｏｄｅ－Ｌｏｃ... 详细信息

ＳｔｕｄｉｅｓｏｎＰａｓｓｉｖｅＭｏｄｅ－ＬｏｃｋｉｎｇＣｈａｒａｃｔｅｒｉｓｔｉｃｓｏｆＮｄ：ＹＡＧＬａｓｅｒＷｉｔｈａＮｏｎｌｉｎｅａｒＣｏｕｐｌｅｄ－ＣａｖｉｔｙＳｔｕｄｉｅｓｏｎＰａｓｓｉｖｅＭｏｄｅ－ＬｏｃｋｉｎｇＣｈａｒａｃｔｅｒｉｓｔｉ...

关键词： Coupled-cavity mode locking resonant passive mode-locking high-repetition-rate laser

Energy Transfer among Chlorophylls in Trimeric Light-harvesting Complex Ⅱ of Bryopsis corticulans

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Acta Biochimica et Biophysica Sinica 2006年第5期38卷 310-317页

作者： Su-Juan ZHANG~(1,2.)Shui-Cai WANG~2.Jun-Fang HE~2.Hui CHEN~3 1 institute of Photonics and Photo-Technology,Northwest University,xi'an 710069,china 2.State Key Laboratory of Transient {2. and Photonics,xi 'an institute of {2. and precision mechanics,Chinese Academy of Sciences,xi'an 710068.china 3 Laboratoty of Photosynthesis Basic Research,institute of Botany,Chinese Academy of Sciences,Beijing 100093,china institute of Photonics and Photo-Technology Northwest UniversityXi'an 710069 China State Key Laboratory of Transient optics and Photonics Xi'an Institute of Optics and Precision Mechanics Chinese Academy of SciencesXi'an 710068 China Laboratory of Photosynthesis Basic Research Institute of Botany Chinese Academy of SciencesBeijing 100093 China

A study on energy transfer among chlorophylls（Chls）in the trimeric unit of the major light-harvesting complex Ⅱ（LHC Ⅱ）from Bryopsis corriculan,was carried out using time-correlated singlephoton *** the chlorophyll Q region of LHC Ⅱ,six molecules characterized as Chlb62.,Chlb646,Chlb652.54,657,Chla664666,Chla674677.680and Chla682.83were discriminated according to their absorption spectrumand fluorescence emission ***,excited by pulsed light of 62. nm,fluorescence kinetics spectrain the chlorophyll Q region were *** accordance with the principles of fluorescence kinetics,thesekinetics data were analyzed with a multi-exponential *** constants on energy transfer were *** overwhelming percentage of energy transfer among chlorophylls undergoes a process longer than 97picoseconds（ps）,which shows that,before transferring energy to another Chl,the excited Chl might convertenergy to vibrations of a lower state with different multiplicity（intersystem crossing）.Energy transfer at thelevel of approximately 10 ps was also obtained,which was interpreted as the excited Chls may go throughinternal conversion before transferring energy to another *** with a higher standard deviation,timeconstants at the femtosecond level can not be entirely excluded,which can be attributed to the ultrafastprocess of direct energy *** to the arrangement and direction of the dipole moment of Chls inLHC Ⅱ,the probability of these processes is *** fluorescence lifetimes of Chlb652.54,657,Chla664666,Chla674677.680and Chla682.83were determined to be 1.44ns,1.43 ns,636 ps and 713 ps,*** of energy dissipation in the pathway of fluorescence emission were no more than 40% in thetrimeric unit of LHC Ⅱ.These results are important for a better understanding of the relationship between thestructure and function of LHC Ⅱ.

关键词： energy transfer LHC Ⅱ transient spectrum fluorescence kinetics

The Design of the Black Patch

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Chinese Journal of Lasers 1996年第3期B5卷 260-267页

作者： GAO Wanrong ZHANG xingzhen PAN Laijiu WANG Jiangang(Space optics Department, xi' an institute of optics and fine mechanics,Academia Sinica, xi' an 710068, china) xi'an Inst of optics and Fine Mechanics Academia Sinica Xi'an China

Ｔｈｅ　Ｄｅｓｉｇｎ　ｏｆ　ｔｈｅ　Ｂｌａｃｋ　ＰａｔｃｈＴｈｅＤｅｓｉｇｎｏｆｔｈｅＢｌａｃｋＰａｔｃｈ￥ＧＡＯＷａｎｒｏｎｇ；ＺＨＡＮＧＸｉｎｇｚｈｅｎ；ＰＡＮＬａｉｊｉｕ；ＷＡＮＧＪｉａｎｇａｎｇ（ＳｐａｃｅＯ... 详细信息

Ｔｈｅ　Ｄｅｓｉｇｎ　ｏｆ　ｔｈｅ　Ｂｌａｃｋ　ＰａｔｃｈＴｈｅＤｅｓｉｇｎｏｆｔｈｅＢｌａｃｋＰａｔｃｈ￥ＧＡＯＷａｎｒｏｎｇ；ＺＨＡＮＧＸｉｎｇｚｈｅｎ；ＰＡＮＬａｉｊｉｕ；ＷＡＮＧＪｉａｎｇａｎｇ（ＳｐａｃｅＯｐｔｉｃｓＤｅｐａｒｔｍｅｎｔ，Ｘ...

关键词： veiling glare index image quality black area design

Electronic structure and magnetism of Fe-doped SiC nanotubes

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Science china(Physics,mechanics & Astronomy) 2010年第9期53卷 1582-1589页

作者： ZHANG WeiHu1,2.3,ZHANG FuChun3,ZHANG ZhiYong4,LU ShuYuan5 & YANG YanNing3 1 xi’an institute of optics and {2. mechanics,Chinese Academy of Sciences,xi’an 710068,china 2.Graduate University of Chinese Academy of Sciences,Beijing 100049,china 3 College of Physics and Electronic Information,Yan’an University,Yan’an 716000,china 4 Information Science and Technology Institution,Northwest University,xi’an 71012.,china 5 Department of Telecommunications,xi’an institute of Posts and Telecommunications,xi’an 71012.,china xi’an institute of optics and {2. mechanics Chinese Academy of Sciences Xi’an China Graduate University of Chinese Academy of Sciences Beijing China College of Physics and Electronic Information Yan’an University Yan’an China Information Science and Technology Institution Northwest University Xi’an China Department of Telecommunications Xi’an Institute of Posts and Telecommunications Xi’an China

The electronic structure and magnetic properties of Fe-doped SiC nanotubes are investigated by using the first-principles method based on density functional theory(DFT) in the local spin density approximation(LSDA).The calculation results indicate that the SiC nanotube of Fe substitution for C exhibits antiferromagnetism while ferromagnetism features prominently when Fe substitutes *** is a kind of half-metal magnetic *** formation energy calculation results show that the formation energy of ferromagnetic structure is 3.2.eV lower than that of antiferromagnetic *** atoms are more likely to replace Si ***-orbit coupling induces electron spin polarization in the ground ***,the doping Fe atoms make relaxation towards the outside of the tube to some extent and larger geometric distortion occurs when Fe substitutes C,but the whole geometric structure of SiC nanotubes is not damaged due to the *** is revealed in the calculation of energy band structure and density of states that more dispersed distribution of energy levels is produced near the Fermi *** Fe substitution for Si,obviously there are spin-split and intense p-d hybrid effects by Si 3p electron spins and Fe 3d electron spins localized at the exchanging interactions between magnetic transitional metal(TM) *** electronic density results indicate that system magnetic moments are mainly generated by the unpaired 3d electrons of Fe *** these results show that the transition metal doping SiC nanotube could be a potential route to fabricating the promising magnetic materials.

关键词： SiC nanotube the first-principles doped magnetic properties

Computer Simulation of the Indentation Creep Tests on Particle-Reinforced Composites

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Journal of Materials Science & Technology 2002年第4期18卷 335-340页

作者： Zhufeng YUE1,2.1)Department of Engineering mechanics, Northwestern Polytechnical University, xi’an 710072. china2.{2. of Materials, Ruhr University, 44780 Bochum, Germany Dept. of Eng. Mech. Northwestern Polytech. Univ. Xi'an 710072 China Inst. of Mat. Ruhr Univ. 44780 Bochum Germany

A systematical simulation has been carried out on the indentation creep test on particle-reinforced composites. The deformation, failure mechanisms and life are analyzed by three reasonable models. The following five factors have been considered simultaneously: creep property of the particle, creep property of the matrix, the shape of the particle, the volume fraction of the particle and the size (relative size to the particle) of the indentation indenter. For all the cases, the power law respecting to the applied stress can be used to model the steady indentation creep depth rate of the indenter, and the detail expressions have been presented. The computer simulation precision is analyzed by the two-phase model and the three-phase model. Two places of the stress concentration are found in the composites. One is ahead of the indentation indenter, where the high stress state is deduced by the edge of the indenter and will decrease rapidly near to a steady value with the creep time. The other one is at the interface, where the high stress state is deduced by the misfit of material properties between the particles and matrix. It has been found that the creep dissipation energy density other than a stress parameter can be used to be the criterion to model the debonding of the interfaces. With the criterion of the critical creep dissipation energy density, a power law to the applied stress with negative exponent can be used to model the failure life deduced by the debonding of interfaces. The influences of the shape of the particles and the matching of creep properties of particle and matrix can be discussed for the failure. With a crack model, the further growth of interface crack is analyzed, and some important experimental phenomena can be predicted. The failure mechanism which the particle will be punched into matrix has been also discussed. The critical differences between the creep properties of the particles and matrix have been calculated, after a parameter has b

关键词： Indentation creep test Particle-reinforced composites Computer simulation Deformation Failure

Experimental study on high power all-fiber laser

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Chinese optics Letters 2010年第4期8卷 404-406页

作者：赵保银段开椋赵卫李成王屹山 State Key Laboratory of Transient optics and Photonics xi'an institute of optics and precision mechanics Chinese Academy of Sciences Graduate University of Chinese Academy of Sciences

A high power all-fiber laser is experimentally studied.A monolithic fiber laser system with only one stage of resonator cavity is constructed and 404-W continuous wave（CW） output power is *** opticalto -optical conversion efficiency is up to 64%.The laser central wavelength is at 1081 nm with the spectral full-width at half-maximum（FWHM） of 2.*** laser setup can work with excellent stability;in the long time of high power operation,no thermal distortions or damages are observed.

关键词： Conversion efficiency