输出功率达230W的绿光固体激光器

介绍了一种高功率Nd:YAG绿光激光器实验装置,采用非垂直入射式漫反聚光腔,解决了高泵浦功率密度下增益分布均匀性问题,采用双泵浦头串联的对称直通谐振腔结构,在LD泵浦功率1 400 W时,获得了400 W基频输出,采用Ⅰ类温度匹配方式LBO晶体内腔倍频,在声光Q开关重复频率10 kHz条件下,获得了平均功率达230 W的532 nm绿光激光输出,脉冲宽度小于56 ns,光一光转换效率16.8%,光束质量约30 mm·mrad.该激光器结构简单,可靠性好,适合于工程应用.     

同步泵浦声光调Q全固态脉冲激光器

本文首次提出了同步泵浦声光调Q全固态脉冲激光器，分析了其基本理论，设计并实现了这种新型激光器。它克服了现有小型全固态脉冲激光器存在寄生多脉冲和峰值功率还不够高的缺点，用2W LD的泵浦时，得到了重复频率为4．5kHz、峰值功率为6kW、脉宽为18ns、无寄生脉冲的连续脉冲激光输出，可以较好地满足激光测距和激光雷达对此类激光器性能的要求。本文对实验方案、设备和结果进行了详细的描述。     

小型化高重频窄脉冲声光Q开关DPL

介绍了小型化高重频声光Q开关DPL研制过程中的一些实验进展和相关产品样机。实验中，通过参数的优化选择，在激光二极管的泵浦峰值功率5 W，重复频率2 500 Hz下得到脉冲能量为81.5 μJ，脉冲宽度约为7.4 ns的激光输出，此时激光器的峰值功率为11 kW，光光转换效率14%，光束质量因子M2约为2.1。     

LD泵浦双调Q Nd:GdVO4激光器实验研究

报道了采用半导体激光器(LD)单端泵浦Nd:GdVO4晶体,在谐振腔内同时利用声光器件、Cr4 :YAG晶体,实现1.06μm激光的双调Q运转.当泵浦功率为7.7w,重复频率为10kHz时,得到最短脉冲宽度20ns,单脉冲能量45.8μJ及相应峰值功率2.29kW的激光脉冲.     

LD泵浦双调Q Nd∶GdVO_4激光器实验研究

报道了采用半导体激光器(LD)单端泵浦Nd:GdVO4晶体,在谐振腔内同时利用声光器件、Cr4+:YAG晶体,实现1.06μm激光的双调Q运转。当泵浦功率为7.7W,重复频率为10kHz时,得到最短脉冲宽度20ns,单脉冲能量45.8μJ及相应峰值功率2.29kW的激光脉冲。     

LD泵浦Nd:GdVO_4/KTP双调Q绿光激光器实验研究

采用半导体激光器(LD)单端泵浦Nd:GdVO4晶体,在谐振腔内同时利用声光器件、Cr4+:YAG晶体和KTP晶体,实现532nm内腔倍频双调Q绿光运转。当泵浦功率为7.7W,重复频率为10kHz时,获得最短脉冲宽度为24ns,单脉冲能量为32.4μJ及相应峰值功率为1.35kW的激光脉冲。     

高重频双端泵浦全固态Nd∶YVO4 声光调Q激光器

采用国产大功率光纤束模块,双端面泵浦两块Nd∶YVO4 激光晶体,采用高衍射效率声光调Q技术,在注入总功率50W,最高重频100kHz的条件下,获得平均输出功率为18. 21W的1064nm激光输出。脉冲宽度为62ns,相应光光转换效率为36. 4%。在最低重频10kHz时,具有最大单脉冲能量1. 3mJ ,相应脉冲宽度为16. 4ns,峰值功率达到了80kW。     

高重频双端泵浦全固态Nd：YVO4声光调Q激光器

采用国产大功率光纤束模块，双端面泵浦两块Nd：YVO4激光晶体，采用高衍射效率声光调Q技术，在注入总功率50W，最高重频100kHz的条件下，获得平均输出功率为18．21W的1064nm激光输出。脉冲宽度为62ns，相应光光转换效率为36．4％。在最低重频10kHz时，具有最大单脉冲能量1．3mJ，相应脉冲宽度为16．4ns，峰值功率达到了80kW。     

LD泵浦Nd∶YVO_4/Cr∶YAG被动调Q绿光激光器

报道了一种 LD近贴泵浦、KTP晶体腔内倍频的 Nd∶ YVO4/Cr∶ YAG结构高重复频率被动调 Q绿光激光器。在注入泵浦功率为 75 0 m W时 ,得到平均功率 86m W、脉冲宽度2 6.6ns、重复频率 79.2 k Hz、峰值功率 41 .1 W的被动调 Q脉冲绿光输出     

高重复频率二极管泵浦激光器窄脉宽调Q技术

文中介绍了二极管泵浦激光器谐振腔中的声光调Q技术 ,计算了超声波渡越时间及其对输出光脉冲的影响。在此基础上 ,设计的调Q二极管泵浦激光器在 15W泵浦下 ,获得了脉宽7ns ,峰值功率 34kW ,重复频率 10kHz的脉冲输出     

Preparation and Characterization of TaN ALD Precursors

High purity organic-tantalum precursors for thin film ALD TaN were synthesized and characterized.Vapor pressure and thermal stability of these precursors were studied.From the vapor pressure analysis,it was found that TBTEMT has a higher vapor pressure than any other published liquid TaN precursor,including TBTDET,TAITMATA,and IPTDET.Thermal stability of the alkyl groups on the precursors was investigated using a 1H NMR technique.The results indicated that the tertbutylimino group is the most stable group on TBTDET and TBTEMT as compared to the dialkylamido groups.Thermal stability of TaN precursors decreased in the following order:TBTDET ＞ PDMAT ＞ TBTEMT.In conclusion,precursor vapor pressure and thermal stability were tuned by making slight variations in the ligand sphere around the metal center.     

Curved crystal spectrometer for the measurement of X-ray lines from laser-produced plasmas

In order to diagnose the laser-produced plasmas, a focusing curved crystal spectrometer has been developed for measuring the X-ray lines radiated from a laser-produced plasmas. The design is based on the fact that the ray emitted from a source located at one focus of an ellipse will converge on the other focus by the reflection of the elliptical surface. The focal length and the eccentricity of the ellipse are 1350 mm and 0.9586, respectively. The spectrometer can be used to measure the X- ray lines in the wavelength range of 0.2-0.37 nm, and a LiF crystal （200） （2d = 0.4027 nm） is used as dispersive element covering Bragg angle from 30° to 67.5°. The spectrometer was tested on Shengnang- Ⅱ which can deliver laser energy of 60-80 J/pulse and the laser wavelength is 0.35 μm. Photographs of spectra including the 1 s2p ^1P1-1s^2 ^1S0 resonance line（w）, the 1s2p ^3P2-1s^2 1S0 magnetic quadrupole line（x）, the 1s2p ^3P1-1 s^2 ^1S0 intercombination lines（y）, the 1 s2p ^3S~1-1 s^2 ^1S0 forbidden line（z） in helium-like Ti Ⅹ Ⅺ and the 1 s2s2p ^2P3/2-1 s622s ^2S1/2 line（q） in lithium-like Ti Ⅹ Ⅹhave been recorded with a X-ray CCD camera. The experimental result shows that the wavelength resolution（λ/△ 2） is above 1000 and the elliptical crystal spectrometer is suitable for X-ray spectroscopy.     

Electronic Structure of Semiconductor Nanocrystals

This paper reviews our recent development of the use of the large-scale pseudopotential method to calculate the electronic structure of semiconductor nanocrystals, such as quantum dots and wires, which often contain tens of thousands of atoms. The calculated size-dependent exciton energies and absorption spectra of quantum dots and wires are in good agreement with experiments. We show that the electronic structure of a nanocrystal can be tuned not only by its size,but also by its shape. Finally,we show that defect properties in quantum dots can be significantly different from those in bulk semiconductors.     

Critical Stage Rule-Based Real Time Dispatch（RTD）System in Highly-Mixed-Products （HMP） FAB

An improving utilization and efficiency of critical equipments in semiconductor wafer fabrication facilities are concerned. Semiconductor manufacturing FAB is one of the most complicated and cost sensitive environments. A good dispatching tool will make big difference in equipment utilization and FAB output as a whole. The equipment in this paper is In-Line DUV Scanner. There are many factors impacting utilization and output on this equipment group. In HMP environment one of the issues is changing of reticule in this area and idle counts due to load unbalance between equipments. Here we'll introduce a rule-based RTD system which aiming at decreasing the number of recipe change and idle counts among a group of scanner equipment in a high-mixed-products FAB.     

GaAsSb/InAlAs PA DHBTs Grown by Production MBE

The epi material growth of GaAsSb based DHBTs with InAlAs emitters are investigated using a 4 × 100mm multi-wafer production Riber 49 MBE reactor fully equipped with real-time in-situ sensors including an absorption band edge spectroscope and an optical-based flux monitor. The state-of-the-art hole mobilities are obtained from 100nm thick carbon-doped GaAsSb. A Sb composition variation of less than ± 0.1 atomic percent across a 4 × 100mm platen configuration has been achieved. The large area InAlAs/GaAsSb/InP DHBT device demonstrates excellent DC characteristics,such as BVCEO＞6V and a DC current gain of 45 at 1kA/cm2 for an emitter size of 50μm × 50μm. The devices have a 40nm thick GaAsSb base with p-doping of 4. 5 × 1019cm-3 . Devices with an emitter size of 4μm × 30μm have a current gain variation less than 2% across the fully processed 100mm wafer. ft and fmax are over 50GHz,with a power efficiency of 50% ,which are comparable to standard power GaAs HBT results. These results demonstrate the potential application of GaAsSb/InP DHBT for power amplifiers and the feasibility of multi-wafer MBE for mass production of GaAsSb-based HBTs.     

Technology innovation and process integrations for sub-100nm gate patterning

This paper presents a brief overview of the Applied Centura(R)DPS(R)system,configured with silicon etch DPS Ⅱ chamber, with emphasis on discussing tuning capability for CD uniformity control. It also presents the studies of etch process chemistry and film integration impact for an overall successful gate patterning development. Discussions will focus on resolutions to key issues, such as CD uniformity, line-edge roughness, and multilayer film etching integration.     

White organic light-emitting devices based on fac tris（2- phenylpyridine） iridium sensitized 5,6,11,12-tetraphenylnap -hthacene

We have fabricated the white organic light-emitting devices （WOLEDs） based on 4,4＇ -bis（2,2 -diphenyl vinyl）-1,1＇ - biphenyl （DPVBi） and phosphorescence sensitized 5,6,11,12,-tetraphenylnaphthacene （rubrene）. The device structure is ITO/2T-NATA （20 nm）/NPBX （20 nm）/CBP： x%Ir（ppy）3：0.5% rubrene （8 nm）/NPBX （5 nm）/DPVBi （30 nm）/Alq（30 nm）/LiF（0.5 nm）/A1. In the devices, DPVBi acts as a blue light-emitting layer, the rubrene is sensitized by a phosphorescent material, fac tris （2-phenylpyridine） iridium [Ir（ppy）3], acts as a yellow light-emitting layer, and N,N＇ -bis- （1-naphthyl）- N,N＇ -diphenyl -1, 1＇ -biphenyl-4,4＇ -diamine （NPBX） acts as a hole transporting and exciton blocker layer, respectively. When the concentration of Ir （PPY）3 is 6wt%, the maximum luminance is 24960 cd/m^2 at an applied voltage of 15 V, and the maximum luminous efficiency is 5.17 cd/A at an applied voltage of 8 V.     

Complete approach to automatic identification and subpixel center location for ellipse feature

To meet the need of automatic image features extraction with high precision in visual inspection, a complete approach to automatic identification and sub-pixel center location for similar-ellipse feature is proposed. In the method, the feature area is identified automatically based on the edge attribute, and the sub-pixel center location is accomplished with the leastsquare algorithm. It shows that the method is valid, practical, and has high precision by experiment. Meanwhile this method can meet the need of instrumentation of visual inspection because of easy realization and without man-machine interaction.     

小角度扩展相关性近似算法分析

本论文提出一种在多天线MIMO信道相关性建模中小角度扩展近似理论算法,并应用于分析MIMO系统性能。分析中分别对三种不同角能量分布情况下的空间相关性研发快速近似计算法,并同时提出双模(Bi-Modal)角能量分布情况下的近似运算。通过分析这些新方法的近似效率,可以得到计算简单、复杂度低、而且符合实际的MIMO相关信道矩阵,对系统级的快速高效计算法的研究和系统级的评估以及误差分析具有重要的意义。     

Noise character analysis and the restraint of self-pulsation laser diodes

We calculate the Langevin noise sources of self-pulsation laser diodes, analyze the effects of active region noise and saturable-absorption region noise on the power fluctuation as well as period fluctuation, and propose a novel method to restrain the noise effects. A visible SIMULINK model is established to simulate the system, The results indicate that the effects of noise in absorption region can be ignored; that with the increase of DC injecting current, the noise effects enhance power jitter, and nevertheless, the period jitter is decreased; and that with external sinusoidal current modulating the self-pulsation laser diode, the noise-induced power jitter and period jitter can be suppressed greatly. This work is valuable for clock recovery in all-optical network.