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Coherent Features of Resonance-Mediated Two-Photon Absorption Enhancement by Varying the Energy Level Structure,Laser Spectrum Bandwidth and Central Frequency
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作者 程文静 梁果 +3 位作者 吴萍 贾天卿 孙真荣 张诗按 《Chinese Physics Letters》 SCIE CAS CSCD 2017年第8期41-45,共5页
The femtosecond pulse shaping technique has been shown to be an effective method to control the multi-photon absorption by the light–matter interaction. Previous studies mainly focused on the quantum coherent control... The femtosecond pulse shaping technique has been shown to be an effective method to control the multi-photon absorption by the light–matter interaction. Previous studies mainly focused on the quantum coherent control of the multi-photon absorption by the phase, amplitude and polarization modulation, but the coherent features of the multi-photon absorption depending on the energy level structure, the laser spectrum bandwidth and laser central frequency still lack in-depth systematic research. In this work, we further explore the coherent features of the resonance-mediated two-photon absorption in a rubidium atom by varying the energy level structure, spectrum bandwidth and central frequency of the femtosecond laser field. The theoretical results show that the change of the intermediate state detuning can effectively influence the enhancement of the near-resonant part, which further affects the transform-limited (TL)-normalized final state population maximum. Moreover, as the laser spectrum bandwidth increases, the TL-normalized final state population maximum can be effectively enhanced due to the increase of the enhancement in the near-resonant part, but the TL-normalized final state population maximum is constant by varying the laser central frequency. These studies can provide a clear physical picture for understanding the coherent features of the resonance-mediated two-photon absorption, and can also provide a theoretical guidance for the future applications. 展开更多
关键词 TL Coherent Features of Resonance-Mediated Two-Photon Absorption Enhancement by Varying the Energy Level structure laser Spectrum Bandwidth and Central Frequency
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Enhancement of photocatalytic activity by femtosecond-laser induced periodic surface structures of Si
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作者 P.Satapathy A.Pfuch +1 位作者 R.Grunwald S.K.Das 《Journal of Semiconductors》 EI CAS CSCD 2020年第3期39-44,共6页
Laser induced periodic surface structures(LIPSS)represent a kind of top down approach to produce highly reproducible nano/microstructures without going for any sophisticated process of lithography.This method is much ... Laser induced periodic surface structures(LIPSS)represent a kind of top down approach to produce highly reproducible nano/microstructures without going for any sophisticated process of lithography.This method is much simpler and cost effective.In this work,LIPSS on Si surfaces were generated using femtosecond laser pulses of 800 nm wavelength.Photocatalytic substrates were prepared by depositing TiO2 thin films on top of the structured and unstructured Si wafer.The coatings were produced by sputtering from a Ti target in two different types of oxygen atmospheres.In first case,the oxygen pressure within the sputtering chamber was chosen to be high(3×10^–2 mbar)whereas it was one order of magnitude lower in second case(2.1×10^–3 mbar).In photocatalytic dye decomposition study of Methylene blue dye it was found that in the presence of LIPSS the activity can be enhanced by 2.1 and 3.3 times with high pressure and low pressure grown TiO2 thin films,respectively.The increase in photocatalytic activity is attributed to the enlargement of effective surface area.In comparative study,the dye decomposition rates of TiO2 thin films grown on LIPSS are found to be much higher than the value for standard reference thin film material Pilkington Activ^TM. 展开更多
关键词 laser induced periodic surface structures nanoripples silicon photocatalytic dye decomposition TiO2 thin film femtosecond laser pulses
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CRYSTAL STRUCTURE AND POWDER DIFFRACTION OF Na_5Y-(WO_4)_4
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作者 何亦宗 黄小荥 《Chinese Journal of Structural Chemistry》 SCIE CAS CSCD 1993年第5期346-349,共4页
Title compound Na5Y (WO4)4 (Mr = 1195. 24) crystallizes in the space group I41/a with the cell parameters a= 11. 447(7), c= 11. 336(1) A , Z = 4, V = 1485(2) A3, A = 5. 34 g/cm3. A(MoKα) = 0. 71069 A. F(000) = 2702, ... Title compound Na5Y (WO4)4 (Mr = 1195. 24) crystallizes in the space group I41/a with the cell parameters a= 11. 447(7), c= 11. 336(1) A , Z = 4, V = 1485(2) A3, A = 5. 34 g/cm3. A(MoKα) = 0. 71069 A. F(000) = 2702, final R = 0. 045,Rw = 0. 054 for 936 observed reflections with I≥3σ(I). The title compound has a scheelite structure.In this paper, we also give the X-ray powder diffraction data of Na5Y(WO4)4 obtained by using a D/max-ra type diffractometer. 展开更多
关键词 Crystal structure laser Material Tungstate Crystal
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Extraction of Laser Stripe Center Line Based on Genetic Algorithm and NURBS Interpolation 被引量:2
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作者 朱文娟 焦开河 +1 位作者 徐春广 肖定国 《Journal of Beijing Institute of Technology》 EI CAS 2008年第2期143-147,共5页
To improve the measurement accuracy of structured laser for inner surface dimensions of a deep hole, a new method to extract the laser stripe center line is proposed. An improved adaptive genetic algorithm that can co... To improve the measurement accuracy of structured laser for inner surface dimensions of a deep hole, a new method to extract the laser stripe center line is proposed. An improved adaptive genetic algorithm that can converge rapidly and search the global optimum is used to determine the threshold for the laser stripe segmentation. And then NURBS interpolation which has a good local control capability is adopted to extract the laser stripe center line. Experiments show that the extracted laser stripe center line is stable and the diameter of the deep hole can be measured accurately. 展开更多
关键词 structured laser center line adaptive genetic algorithm NURBS interpolation
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Three-dimensionalization via control of laser-structuring parameters for high energy and high power lithium-ion battery under various operating con ditions 被引量:1
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作者 Junsu Park Hyeongi Song +6 位作者 Inseok Jang Jaepil Lee Jeongwook Um Seong-guk Bae Jihun Kim Sungho Jeong Hyeong-Jin Kim 《Journal of Energy Chemistry》 SCIE EI CAS CSCD 2022年第1期93-102,I0004,共11页
Laser-structuring is an effective method to promote ion diffusion and improve the performance of lithium-ion battery(LIB)electrodes.In this work,the effects of laser structuring parameters(groove pitch and depth)on th... Laser-structuring is an effective method to promote ion diffusion and improve the performance of lithium-ion battery(LIB)electrodes.In this work,the effects of laser structuring parameters(groove pitch and depth)on the fundamental characteristics of LIB electrode,such as interfacial area,internal resistances,material loss and electrochemical performance,are investigated,LiNi_(0.5)Co_(0.2)Mn_(0.3)O_(2) cathodes were structured by a femtosecond laser by varying groove depth and pitch,which resulted in a material loss of 5%-14%and an increase of 140%-260%in the in terfacial area between electrode surface and electrolyte.It is shown that the importance of groove depth and pitch on the electrochemical performance(specific capacity and areal discharge capacity)of laser-structured electrode varies with current rates.Groove pitch is more im porta nt at low current rate but groove depth is at high curre nt rate.From the mapping of lithium concentration within the electrodes of varying groove depth and pitch by laser-induced breakdown spectroscopy,it is verified that the groove functions as a diffusion path for lithium ions.The ionic,electronic,and charge transfer resistances measured with symmetric and half cells showed that these internal resistances are differently affected by laser structuring parameters and the changes in porosity,ionic diffusion and electronic pathways.It is demonstrated that the laser structuring parameters for maximum electrode performance and minimum capacity loss should be determined in consideration of the main operating conditions of LIBs. 展开更多
关键词 Lithium-ion battery laser structuring Energy density Power density laser induced breakdown spectroscopy Lithium-ion diffusion
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Recent progress in laser texturing of battery materials: a review of tuning electrochemical performances, related material development, and prospects for large-scale manufacturing 被引量:2
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作者 Wilhelm Pfleging 《International Journal of Extreme Manufacturing》 EI 2021年第1期25-44,共20页
Traditional electrode manufacturing for lithium-ion batteries is well established,reliable,and has already reached high processing speeds and improvements in production costs.For modern electric vehicles,however,the n... Traditional electrode manufacturing for lithium-ion batteries is well established,reliable,and has already reached high processing speeds and improvements in production costs.For modern electric vehicles,however,the need for batteries with high gravimetric and volumetric energy densities at cell level is increasing;and new production concepts are required for this purpose.During the last decade,laser processing of battery materials emerged as a promising processing tool for either improving manufacturing flexibility and product reliability or enhancing battery performances.Laser cutting and welding already reached a high level of maturity and it is obvious that in the near future they will become frequently implemented in battery production lines.This review focuses on laser texturing of electrode materials due to its high potential for significantly enhancing battery performances beyond state-of-the-art.Technical approaches and processing strategies for new electrode architectures and concepts will be presented and discussed with regard to energy and power density requirements.The boost of electrochemical performances due to laser texturing of energy storage materials is currently proven at the laboratory scale.However,promising developments in high-power,ultrafast laser technology may push laser structuring of batteries to the next technical readiness level soon.For demonstration in pilot lines adapted to future cell production,process upscaling regarding footprint area and processing speed are the main issues as well as the economic aspects with regards to CapEx amortization and the benefits resulting from the next generation battery.This review begins with an introduction of the three-dimensional battery and thick film concept,made possible by laser texturing.Laser processing of electrode components,namely current collectors,anodes,and cathodes will be presented.Different types of electrode architectures,such as holes,grids,and lines,were generated;their impact on battery performances are illustrated.The usage of high-energy materials,which are on the threshold of commercialization,is highlighted.Battery performance increase is triggered by controlling lithium-ion diffusion kinetics in liquid electrolyte filled porous electrodes.This review concludes with a discussion of various laser parameter tasks for process upscaling in a new type of extreme manufacturing. 展开更多
关键词 laser structuring lithium-ion battery electrode architecture 3D battery cell performance upscaling
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Room-Temperature Continuous-Wave Operation of InGaN-Based Blue-Violet Laser Diodes with a Lifetime of 15.6 Hours 被引量:2
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作者 曾畅 张书明 +13 位作者 季莲 王怀兵 赵德刚 朱建军 刘宗顺 江德生 曹青 种明 段俐宏 王海 史永生 刘素英 杨辉 陈良惠 《Chinese Physics Letters》 SCIE CAS CSCD 2010年第11期129-132,共4页
We report our recent progress of investigations on InGaN-based blue-violet laser diodes (LDs). The roomtemperature (RT) cw operation lifetime of LDs has extended to longer than 15.6 h. The LD structure was grown o... We report our recent progress of investigations on InGaN-based blue-violet laser diodes (LDs). The roomtemperature (RT) cw operation lifetime of LDs has extended to longer than 15.6 h. The LD structure was grown on a c-plane free-standing (FS) GaN substrate by metal organic chemical vapor deposition (MOCVD). The typical threshold current and voltage of LD under RT cw operation are 78 mA and 6.8 V, respectively. The experimental analysis of degradation of LD performances suggests that after aging treatment, the increase of series resistance and threshold current can be mainly attributed to the deterioration of p-type ohmic contact and the decrease of internal quantum efticiency of multiple quantum well (MQW), respectively. 展开更多
关键词 Surfaces interfaces and thin films Optics quantum optics and lasers Condensed matter: structural mechanical & thermal
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Effect of Vacuum on the Laser-Induced Damage of Anti-Reflection Coatings 被引量:1
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作者 凌秀兰 赵元安 +3 位作者 李大伟 周明 邵建达 范正修 《Chinese Physics Letters》 SCIE CAS CSCD 2009年第7期126-129,共4页
In the comparison of damage modifications, absorption measurement and energy dispersive x-ray analysis, the effect of vacuum on the laser-induced damage of anti-reflection coatings is analyzed. It is found that vacuum... In the comparison of damage modifications, absorption measurement and energy dispersive x-ray analysis, the effect of vacuum on the laser-induced damage of anti-reflection coatings is analyzed. It is found that vacuum decreases the laser-induced damage threshold of the films. The low laser-induced damage threshold in vacuum environments as opposed to air environments is attributed to water absorption and the formation of the O/Si, O/Zr sub-stoichiometry in the course of laser irradiation. 展开更多
关键词 OPTICS quantum optics and lasers Condensed matter: structural mechanical & thermal
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Structural deformation of nitro group of nitromethane molecule in liquid phase in an intense femtosecond laser field
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作者 王畅 吴红琳 +1 位作者 宋云飞 杨延强 《Chinese Physics B》 SCIE EI CAS CSCD 2017年第9期228-233,共6页
The structural deformation of NO2 group induced by an intense femtosecond laser field of liquid nitromethane(NM)molecule is detected by time-and frequency-resolved coherent anti-Stokes Raman spectroscopy(CARS) tec... The structural deformation of NO2 group induced by an intense femtosecond laser field of liquid nitromethane(NM)molecule is detected by time-and frequency-resolved coherent anti-Stokes Raman spectroscopy(CARS) technique with the intense pump laser. Here, we present the mechanism of molecular alignment and deformation. The CARS spectra and its FFT spectra of liquid NM show that the NO2 torsional mode couples with the CN symmetric stretching mode and that the NO2 group undergoes ultrafast structural deformation with a relaxation time of 195 fs. The frequency of the NO2 torsional mode in liquid NM(50.8±0.3 cm^-1) at room temperature is found. Our results prove the structural deformation of two groups in liquid NM molecule occur simultaneously in the intense laser field. 展开更多
关键词 coherent anti-Stokes Raman spectroscopy(CARS) spectra structural deformation intense laser field liquid nitromethane
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High Characteristic Temperature 1.3μm InAs/GaAs Quantum-Dot Lasers Grown by Molecular Beam Epitaxy 被引量:1
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作者 季海铭 杨涛 +4 位作者 曹玉莲 徐鹏飞 谷永先 马文全 王占国 《Chinese Physics Letters》 SCIE CAS CSCD 2010年第2期285-287,共3页
We report the molecular beam epitaxy growth of 1.3 μm InAs/GaAs quantum-dot (QD) lasers with high characteristic temperature T0. The active region of the lasers consists of five-layer InAs QDs with p-type modulatio... We report the molecular beam epitaxy growth of 1.3 μm InAs/GaAs quantum-dot (QD) lasers with high characteristic temperature T0. The active region of the lasers consists of five-layer InAs QDs with p-type modulation doping. Devices with a stripe width of 4 μm and a cavity length of 1200 μm are fabricated and tested in the pulsed regime under different temperatures. It is found that T0 of the QD lasers is as high as 532 K in the temperature range from 10°C to 60°C. In addition, the aging test for the lasers under continuous wave operation at 100°C for 72 h shows almost no degradation, indicating the high crystal quality of the devices. 展开更多
关键词 Surfaces interfaces and thin films Optics quantum optics and lasers Nanoscale science and low-D systems Condensed matter: structural mechanical & thermal
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Equivalent Method of Solving Quantum Efficiency of Reflection-Mode Exponential Doping GaAs Photocathode 被引量:3
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作者 牛军 杨智 常本康 《Chinese Physics Letters》 SCIE CAS CSCD 2009年第10期99-101,共3页
The mathematical expression of the electron diffusion and drift length LDE of exponential doping photocathode is deduced. In the quantum efficiency equation of the reflection-mode uniform doping cathode, substituting ... The mathematical expression of the electron diffusion and drift length LDE of exponential doping photocathode is deduced. In the quantum efficiency equation of the reflection-mode uniform doping cathode, substituting LDE for LD, the equivalent quantum efficiency equation of the reflection-mode exponential doping cathode is obtained. By using the equivalent equation, theoretical simulation and experimental analysis shows that the equivalent index formula and formula-doped cathode quantum efficiency results in line. The equivalent equation avoids complicated calculation, thereby simplifies the process of solving the quantum efficiency of exponential doping photocathode. 展开更多
关键词 Electronics and devices Optics quantum optics and lasers Condensed matter: structural mechanical & thermal
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810-nm InGaAlAs/AlGaAs double quantum well semiconductor lasers with asymmetric waveguide structures 被引量:2
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作者 李林 刘国军 +4 位作者 李占国 李梅 王晓华 李辉 万春明 《Chinese Optics Letters》 SCIE EI CAS CSCD 2008年第4期268-270,共3页
The 810-nm InGaAlAs/AlGaAs double quantum well (QW) semiconductor lasers with asymmetric waveguide structures, grown by molecular beam epitaxy, show high quantum efficiency and high-power conver- sion efficiency at ... The 810-nm InGaAlAs/AlGaAs double quantum well (QW) semiconductor lasers with asymmetric waveguide structures, grown by molecular beam epitaxy, show high quantum efficiency and high-power conver- sion efficiency at continuous-wave (CW) power output. The threshold current density and slope efficiency of the device are 180 A/cm^2 and 1.3 W/A, respectively. The internal loss and the internal quantum efficiency are 1.7 cm^-1 and 93%, respectively. The 70% maximum power conversion efficiency is achieved with narrow far-field patterns. 展开更多
关键词 GAAS WELL nm InGaAlAs/AlGaAs double quantum well semiconductor lasers with asymmetric waveguide structures
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AlGaN-Based Deep-Ultraviolet Light Emitting Diodes Fabricated on AlN/sapphire Template 被引量:4
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作者 桑立雯 秦志新 +11 位作者 方浩 张延召 李涛 许正昱 杨志坚 沈波 张国义 李书平 杨伟煌 陈航洋 刘达义 康俊勇 《Chinese Physics Letters》 SCIE CAS CSCD 2009年第11期219-222,共4页
We report on the growth and fabrication of deep ultraviolet (DUV) light emitting diodes (LEDs) on an AIN template which was grown on a pulsed atomic-layer epitaxial buffer layer. Threading dislocation densities i... We report on the growth and fabrication of deep ultraviolet (DUV) light emitting diodes (LEDs) on an AIN template which was grown on a pulsed atomic-layer epitaxial buffer layer. Threading dislocation densities in the AlN layer are greatly decreased with the introduction of this buffer layer. The crystalline quality of the AlGaN epilayer is further improved by using a low-temperature GaN interlayer between AlGaN and AlN. Electroluminescences of different DUV-LED devices at a wavelength of between 262 and 317nm are demonstrated. To improve the hole concentration of p-type AlGaN, Mg-doping with trimethylindium assistance approach is performed. It is found that the serial resistance of DUV-LED decreases and the performance of DUV-LED such as EL properties is improved. 展开更多
关键词 Condensed matter: electrical magnetic and optical Electronics and devices Optics quantum optics and lasers Condensed matter: structural mechanical & thermal
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On-chip mode-locked laser diode structure using multimode interference reflectors 被引量:1
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作者 C.Gordón R.Guzmán +1 位作者 X.Leijtens G.Carpintero 《Photonics Research》 SCIE EI 2015年第1期15-18,共4页
We report, for the first time to our knowledge, an on-chip mode-locked laser diode(OCMLLD) that employs multimode interference reflectors to eliminate the need of facet mirrors to form the cavity. The result is an OCM... We report, for the first time to our knowledge, an on-chip mode-locked laser diode(OCMLLD) that employs multimode interference reflectors to eliminate the need of facet mirrors to form the cavity. The result is an OCMLLD that does not require cleaved facets to operate, enabling us to locate this OCMLLD at any location within the photonic chip. This OCMLLD provides a simple source of optical pulses that can be inserted within a photonic integrated circuit chip for subsequent photonic signal processing operations within the chip(modulation, optical filtering, pulse rate multiplication, and so on). The device was designed using standardized building blocks of a generic active/passive In P technology platform, fabricated in a multi-project wafer run, and achieved mode-locking operation at its fundamental frequency, given the uncertainty at the design step of the optical length of these mirrors, critical to achieve colliding pulse mode-locked operation. 展开更多
关键词 mode On-chip mode-locked laser diode structure using multimode interference reflectors
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Energy Transfer from Ce^3+ to Eu^2+ in LiSrBO3 and Its Potential Application in UV-LED-Based White LEDs 被引量:3
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作者 王志军 李盼来 +2 位作者 杨志平 郭庆林 傅广生 《Chinese Physics Letters》 SCIE CAS CSCD 2009年第11期223-226,共4页
Ce3+/Eu2+ codoped LiSrBO3 phosphor is synthesized, and its luminescent characteristics are investigated. LiSrBO3:Ce3+,Eu2+ phosphor exhibits varied hues from blue to white and eventually to yellow by resonance-ty... Ce3+/Eu2+ codoped LiSrBO3 phosphor is synthesized, and its luminescent characteristics are investigated. LiSrBO3:Ce3+,Eu2+ phosphor exhibits varied hues from blue to white and eventually to yellow by resonance-type energy transfer from Ce3+ ion to Eu2+ ion and tuning the relative proportion of Ce3+/Eu2+ properly. Energy transfer mechanism in LiSrBOa:Ce3+, Eu2+ phosphor is dominated by the dipole-dipole interaction, and the critical distance of the energy transfer is estimated to be about 2 nm by both spectral overlap and concentration quenching methods. Under UV radiation, white light is generated by coupling 436 and 565nm emission bands attributed to Ce3+ and Eu2+ radiations, respectively. 展开更多
关键词 Electronics and devices Condensed matter: electrical magnetic and optical Optics quantum optics and lasers Condensed matter: structural mechanical & thermal
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Design and Fabrication of an Er-Doped Silica Optical Fiber with Six Photosensitive Subcores 被引量:1
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作者 李坚 王静 +5 位作者 刘鹏 鲁韶华 毛向桥 江微微 宁提纲 简水生 《Chinese Physics Letters》 SCIE CAS CSCD 2009年第7期147-149,共3页
A type of multi-core Er-doped photosensitive silica optical fiber (MC-EDPF) is proposed and fabricated, in which a high consistency Er-doped core is surrounded by six high consistency Ge-doped cores. The multi-core ... A type of multi-core Er-doped photosensitive silica optical fiber (MC-EDPF) is proposed and fabricated, in which a high consistency Er-doped core is surrounded by six high consistency Ge-doped cores. The multi-core design can overcome the difficulties encountered in the design and fabrication of single-core EDPFs through a modified chemical vapor deposition method combined with solution doping technology, and there is a conflict between high consistency Er doping and high consistency Ce doping. The absorption of MC-EDPFs achieved 15.876dB/m at 1550mm and lOdB/m at 98Ohm. The refleetivity of the fiber Bragg gratings (FBCs) written directly on the MC-EDPFs is as much as 96.84%. 展开更多
关键词 Optics quantum optics and lasers Condensed matter: structural mechanical & thermal
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Generation of micro/nano hybrid surface structures on copper by femtosecond pulsed laser irradiation 被引量:3
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作者 Ayumi Nakajima Masaki Omiya Jiwang Yan 《Nanomanufacturing and Metrology》 EI 2022年第3期274-282,共9页
The delamination of copper lead frames from epoxy molding compounds(EMC)is a severe problem for microelectronic devices,as it leads to reduced heat dissipation or circuit breakage.The micro/nanoscale surface structuri... The delamination of copper lead frames from epoxy molding compounds(EMC)is a severe problem for microelectronic devices,as it leads to reduced heat dissipation or circuit breakage.The micro/nanoscale surface structuring of copper is a promising method to improve the copper-EMC interfacial adhesion.In this study,the generation of micro/nano hybrid structures on copper surfaces through femtosecond pulsed laser irradiation is proposed to improve interfacial adhesion.The micro/nano hybrid structures were realized by generating nanoscale laser-induced periodic surface structures(LIPSS)on microscale parallel grooves.Several types of hybrid surface structures were generated by changing the laser polarization direction,fluence,and scanning speed.At a specific aspect ratio of microgrooves,a latticed structure was generated on the sides of microgrooves by combining LIPSS formation and direct laser interference patterning.This study provides an efficient method for the micro/nanoscale hybrid surface structure formation for interfacial adhesion improvement between copperand EMC. 展开更多
关键词 Femtosecond pulsed laser COPPER Metal surface LIPSS Direct laser interference patterning-Micro/nano hybrid structures
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MOCVD growth of AlGaInP/GaInP quantum well laser diode with asymmetric cladding structure for high power applications 被引量:2
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作者 李沛旭 王翎 +5 位作者 李树强 夏伟 张新 汤庆敏 任忠祥 徐现刚 《Chinese Optics Letters》 SCIE EI CAS CSCD 2009年第6期489-491,共3页
In order to improve the characteristics of the general broad-waveguide 808-nm semiconductor laser diode (LD), we design a new type quantum well LD with an asymmetric cladding structure. The structure is grown by met... In order to improve the characteristics of the general broad-waveguide 808-nm semiconductor laser diode (LD), we design a new type quantum well LD with an asymmetric cladding structure. The structure is grown by metal organic chemical vapor deposition (MOCVD). For the devices with 100-ttm-wide stripe and 1000-/zm-long cavity under continuous-wave (CW) operation condition, the typical threshold current is 190 mA, the slope efficiency is 1.31 W/A, the wall-plug efficiency reaches 63%, and the maximum output power reaches higher than 7 W. And the internal absorption value decreases to 1.5 cm^-1. 展开更多
关键词 MOCVD growth of AlGaInP/GaInP quantum well laser diode with asymmetric cladding structure for high power applications well high
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Self-Assembled Colloidal Crystals in Capillary with Its Fiber Junction 被引量:1
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作者 喻平 欧红叶 《Chinese Physics Letters》 SCIE CAS CSCD 2009年第10期188-191,共4页
Silica microspheres self-assembled in glass capillary are investigated. Monodisperse silica microsphere dispersions in diameter 320nm are self-organized into a bulk cylindrical colloidal crystal by evaporation induced... Silica microspheres self-assembled in glass capillary are investigated. Monodisperse silica microsphere dispersions in diameter 320nm are self-organized into a bulk cylindrical colloidal crystal by evaporation induced nucleation and crystallization. The resulting colloidal crystals are characterized by optical microscopy and scanning electronic microscopy (SEM), and the SEM images show these crystals dominate in fcc lattice with its (111) crystallographic axis as longitudinal. The colloidal crystal filled capillary is packaged into a heat-shrink plastic tube and a fiber measurement system is designed to measure the optical property of colloidal bulk in capillary. It is found that an appreciable bandgap appears at wavelength 686 nm from the transmission spectroscopy, which is consistent with the theoretical estimation. A considerable photonic band gap of up to -10 dB and a steep photonic band edge of up to 0.25 dB/nm indicate that silica microspheres are promising for implementing optical filter applications in fiber systems. 展开更多
关键词 Soft matter liquids and polymers Optics quantum optics and lasers Condensed matter: structural mechanical & thermal Chemical physics and physical chemistry
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Implant Depth Influence on InGaAsP/InP Double Quantum Well Intermixing Induced by Phosphorus Ion Implantation
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作者 赵杰 陈杰 +1 位作者 王永晨 韩德俊 《Chinese Physics Letters》 SCIE CAS CSCD 2006年第4期919-921,共3页
We investigate quantum well intermixing of a double-quantum-well structure caused by phosphorus ion implantation by means of photoluminescence (PL). The ion implantation is performed at the energy of 120keV with the... We investigate quantum well intermixing of a double-quantum-well structure caused by phosphorus ion implantation by means of photoluminescence (PL). The ion implantation is performed at the energy of 120keV with the dose ranging from 1 × 10^11 to 1 × 10^14/cm^2. The rapid thermal annealing is performed at the temperature of 700℃ for 30s under pure nitrogen protection. The PL measurement shows that the band gap blueshift is influenced by the depth of ion implantation. The blueshift of the upper well which is closer to the implanted wcancies is enhanced with the ion dose faster than that from a lower well under the lower dose implantation (〈 5 × 10^11/cm^2). When the ion dose is over 10^12/cm^2, the band gap blueshift from both the wells increases with the ion dose and finally the two peaks combine together as one peak, indicating that the ion implantation results in a total intermixing of both the quantum wells. 展开更多
关键词 laser structureS PHOTOLUMINESCENCE FABRICATION
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