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A scanning distortion correction method based on Ⅹ-Y galvanometer Lidar system

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Chinese Physics B 2021年第4期30卷 257-263页

作者： Bao-Ling Qi Chun-Hui Wang Dong-Bing Guo Bin Zhang key laboratory of Tunable laser technology Harbin Institute of TechnologyHarbin 150001China

Aiming at the problem of scanning distortion in X-Y galvanometer light detecting and ranging(Lidar) scanning system,we propose a method of image scanning distortion correction with controllable driving voltage ***,the geometrical optics vectors model is established to explain the principle of pincushion distortion in the galvanometer scanning system,and the simulation result of scanning trajectory is consistent with *** linear relationship between the driving voltage and the scanning angle of the galvanometer is ***,the relationship between the deflection angle of the galvanometer and the scanning trajectory and the driving voltage is deduced respectively,and an image scanning correction algorithm with controllable driving voltage compensation is *** simulation experiment results of the proposed method show that the root-mean-square error(RMSE) and the corresponding curve between the scan value and the actual value at different distances,have a good correction effect for the pincushion ***,the X-Y galvanometer scanning Lidar system is established to obtain undistorted two-dimensional scanned image and it can be applied to the three-dimensional Lidar scanning system in the actual experiments,which further demonstrates the feasibility and practicability of our method.

关键词： Lidar laser scanning optical vector model image scanning

High-power passively Q-switched 2 μm all-solid-state laser based on a Bi_2Te_3 saturable absorber

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Photonics Research 2017年第5期5卷 461-466页

作者： X.LIU K.YANG S.ZHAO T.LI W.QIAO H.ZHANG B.ZHANG J.HE J.BIAN L.ZHENG L.SU J.XU School of Information Science and Engineering and Shandong Provincial Key Laboratory of Laser Technology and ApplicationShandong University State key laboratory of Crystal material Shandong University State key laboratory of Pulsed Power laser technology key laboratory of Transparent and Opto-functional Inorganic materials Artificial Crystal Research Center Shanghai Institute of CeramicsChinese Academy of Sciences School of Physics Science and Engineering Institute for Advanced Study Tongji University

By using the ultrasound-assisted liquid phase exfoliation method, Bi_2Te_3 nanosheets are synthesized and deposited onto a quartz plate to form a kind of saturable absorber(SA), in which nonlinear absorption properties around 2 μm are analyzed with a home-made mode-locked laser. With the as-prepared Bi_2Te_3 SA employed,a stable passively Q-switched all-solid-state 2 μm laser is successfully realized. Q-switched pulses with a maximum average output power of 2.03 W are generated under an output coupling of 5%, corresponding to the maximum single-pulse energy of 18.4 μJ and peak power of 23 W. The delivered shortest pulse duration and maximum repetition rate are 620 ns and 118 k Hz under an output coupling of 2%, respectively. It is the first presentation of such Bi_2Te_3 SA employed in a solid-state Q-switched crystalline laser at 2 μm, to the best of our knowledge. In comparison with other 2 D materials suitable for pulsed 2 μm lasers, the saturable absorption performance of Bi_2Te_3 SA is proved to be promising in generating high power and high-repetition-rate 2 μm laser pulses.

关键词： Te SA m all-solid-state laser based on a Bi2Te3 saturable absorber High-power passively Q-switched 2 Bi

Observation of Periodic Multiplication and Chaotic Phenomena in Atmospheric Cold Plasma Jets

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Chinese Physics Letters 2008年第9期25卷 3323-3325页

作者：齐冰黄建军张哲皇王德真 School of Physics Science and technology Shenzhen University Shenzhen 518060 State key laboratory of materials Modification by laser Ion and Electron Beams School of Physics and Optoelectronic Technology Dalian University of Technology Dalian 116023

We investigate the temporal evolution of the current pulses from an ac Fie cold plasma jet at atmospheric pressure and with driving frequency in the range 14.76-15.30 kHz. The driving frequency is used as the plasma system＇s bifurcation parameter in analogy with the evolution in which the current pulses undergoes multiplication and chaos. Such time-domain nonlineaxity is important for controlling instabilities in atmospheric glow discharges. In addition, the observation can provide some data to support the simulation results reported previously [Appl. Phys. Lett. 90 （2007） 071501].

关键词： the power-law exponents precipitation durative abrupt precipitation change

A power and wavelength detuning-dependent hysteresis loop in a single mode Fabry-Prot laser diode

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Chinese Physics B 2013年第8期22卷 434-438页

作者：吴建伟 Bikash Nakarmi Chongqing key laboratory of Optoelectronic Functional material Chongqing Normal University State key laboratory of Millimeter Waves Department of Electrical Engineering Korea Advanced Institute of Science and Technology Department of Information and Communication Engineering Korea Advanced Institute of Science and Technology

In this paper, we observe experimentally the optical bistability induced by the side-mode injection power and wave- length detuning in a single mode Fabry-P6rot laser diode （SMFP-LD）. Results show that the bistability characteristics of the dominant and injected modes are strongly dependent on the injected input optical power and wavelength detuning in an SMFP-LD. We observe three types of hysteresis loops： counterclockwise, clockwise, and butterfly hysteresis with various loop widths. In the case of a bistability loop caused by injection power, the transition from counterclockwise to clockwise in the hysteresis direction with the wavelength detuning from 0.028 nm to 0.112 nm is observed in a way of butterfly hys- teresis for the dominant mode by increasing the wavelength detuning. The width of hysteresis loop, induced by wavelength detuning is also changed while the injection power is enhanced from -7 dBm to -5 dBm.

关键词： single mode Fabry-P6rot laser diode injection locking behavior optical bistability

Coupling effects of SiC and TiB_(2) particles on crack inhibition in Al-Zn-Mg-Cu alloy produced by laser powder bed fusion

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Journal of materials Science & technology 2023年第33期164卷 37-51页

作者： Ning Li Ting Wang Lixia Zhang Liang Zhang State key laboratory of advanced Welding and Joining Harbin Institute of Technology at WeihaiWeihai 264209China Shandong Provincial key laboratory of Special Welding technology Harbin Institute of Technology at WeihaiWeihai 264209China Institute of Intelligent Manufacturing technology Shenzhen PolytechnicShenzhen 518055China

A novel Al-Zn-Mg-Cu alloy free of cracks was produced utilizing laser powder bed fusion(LPBF)and modified with SiC and TiB_(2) *** interdependent effects of SiC and TiB_(2) particles on morphology,microstructure,and crystallographic texture were *** mechanisms behind phase evolution and crack inhibition were *** results show that a nearly dense Al-Zn-Mg-Cu alloy could be obtained when the mass fraction of SiC and TiB2 particles was 4%.TiB_(2) particles remained stable and acted as nucleation agents in the molten *** SiC particles reacted with the Al matrix to form rod-like Al_(4)C_(3),lamellate Al_(4)SiC_(4),and flocculent Si phases,which provided nucleation agents and liquid replenishment for matrix *** columnar grains of the matrix were refined into equiaxed grains,and the average size decreased from 37.15μm to 7.54μ*** preferential growth of grains along the(001)〈001〉direction was suppressed and transformed into a disordered random *** innovative Al-Zn-Mg-Cu alloy demonstrated an ultimate tensile strength of 492±12 MPa and an elongation of 7.2%±0.7%.The microhardness was enhanced,and the microhardness heterogeneity was *** solidification properties were regulated,the temperature interval between solidus and liquidus was narrowed,and the liquidity of the molten pool was *** hot cracking of Al-Zn-Mg-Cu alloy was inhibited due to the interdependent effects of grain refinement by TiB2 particles and sufficient liquid metal replenishment by SiC particles.

关键词： laser powder bed fusion Solidification cracks Al-Zn-Mg-Cu alloys In-situ reaction Microstructure evolution

Continuous-wave operation of a room-temperature Tm:YAP-pumped Ho:YAG laser

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Chinese Optics Letters 2008年第7期6卷 520-522页

作者：姚宝权段小明李玉峰郑亮亮王月珠赵广军徐军 National key laboratory of Tunable laser technology Harbin Institute of TechnologyHarbin 150001 laser and Optoelectronic Functional material It and D Center Shanghai Institute of Optics and Fine MechanicsChinese Academy of SciencesShanghai 201800

We report a continuous-wave （CW） 2.1-μm Ho：YAG laser operating at room temperature pumped by a diode-pumped 1.94-μm Tm：YAP laser. The maximum output power of 1.5 W is obtained from Ho：YAG laser, corresponding t... 详细信息

关键词： Conversion efficiency Fiber lasers lasers

Preparation of TiO_(x)/γ-Al_(2)O_(3) Catalyst on Powdery γ-Al_(2)O_(3) by Using Reactive Sputtering Deposition

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Chinese Physics Letters 1999年第6期16卷 426-427页

作者： LU Wen-qi XU Zhen-feng DENG Xin-lu XU Jun ZHANG Jia-liang ZHU Ai-min GONG Wei-min State key laboratory for material Modification by laser Ion and Electron BeamsDalian University of TechnologyDalian 116024 Dandong Textile College Dandong 118003

A layer of TiO_(x) was deposited on powdery γ-Al_(2)O_(3) by using Sat-target magnetron sputtering in microwave electron cyclotron resonance plasma.A vibrator was developed to coat the γ-Al_(2)O_(3) particles evenly by TiO_(x).The conversion efficiency of methane and both the yield and the selectivity of C_(2) hydrocarbons and C_(2)H_(2) were revealed to be superior to that by conventional chemical *** use of vibrator is effective.

关键词： method. (x) evenly

H-and J-aggregation of conjugated small molecules in organic solar cells

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Journal of Energy Chemistry 2024年第6期93卷 174-192,I0005页

作者： Qiaoqiao Zhao Feng He State key laboratory of Biobased material and Green Papermaking Qilu University of TechnologyShandong Academy of SciencesJinan 250353ShangdongChina shenzhen Grubbs Institute and Department of Chemistry Southern University of Science and TechnologyShenzhen 518055GuangdongChina Guangdong Provincial key laboratory of Catalysis Southern University of Science and TechnologyShenzhen 518055GuangdongChina

As H-and J-aggregation receive more and more attention in the research of organic solar cells(OSCs),especially in small molecular systems,deep understanding of aggregation behavior is needed to guide the design of conjugated small molecular structure and the fabrication process of OSC *** this end,this review is ***,the review firstly introduced the basic information about H-and J-aggregation of conjugated small molecules in ***,the characteristics of H-and J-aggregation and the methods to identify them were ***,it reviewed the research progress of H-and J-aggregation of conjugated small molecules in OSCs,including the factors influencing H-and J-aggregation in thin film and the effects of H-and J-aggregation on OPV performance.

关键词： H-aggregation J-aggregation Organic solar cells Small molecules Efficiency Stability

Multilevel carbon architecture of subnanoscopic silicon for fast‐charging high‐energy‐density lithium‐ion batteries

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Carbon Energy 2024年第4期6卷 256-268页

作者： Meisheng Han Yongbiao Mu Lei Wei Lin Zeng Tianshou Zhao shenzhen key laboratory of advanced Energy Storage Southern University of Science and TechnologyShenzhenChina SUSTech Energy Institute for Carbon Neutrality Southern University of Science and TechnologyShenzhenChina Department of Mechanical and Energy Engineering Southern University of Science and TechnologyShenzhenChina

Silicon(Si)is widely used as a lithium‐ion‐battery anode owing to its high capacity and abundant crustal ***,large volume change upon cycling and poor conductivity of Si cause rapid capacity decay and poor fast‐charging capability limiting its commercial ***,we propose a multilevel carbon architecture with vertical graphene sheets(VGSs)grown on surfaces of subnanoscopically and homogeneously dispersed Si–C composite nanospheres,which are subsequently embedded into a carbon matrix(C/VGSs@Si–C).Subnanoscopic C in the Si–C nanospheres,VGSs,and carbon matrix form a three‐dimensional conductive and robust network,which significantly improves the conductivity and suppresses the volume expansion of Si,thereby boosting charge transport and improving electrode *** VGSs with vast exposed edges considerably increase the contact area with the carbon matrix and supply directional transport channels through the entire material,which boosts charge *** carbon matrix encapsulates VGSs@Si–C to decrease the specific surface area and increase tap density,thus yielding high first Coulombic efficiency and electrode compaction ***,C/VGSs@Si–C delivers excellent Li‐ion storage performances under industrial electrode *** particular,the full cells show high energy densities of 603.5 Wh kg^(−1)and 1685.5 Wh L^(−1)at 0.1 C and maintain 80.7%of the energy density at 3 C.

关键词： fast charging high energy densities lithium‐ion batteries multilevel carbon architecture subnanoscopic silicon anode