共查询到20条相似文献,搜索用时 187 毫秒
1.
2.
An investigation of pulsed laser cutting of titanium alloy sheet 总被引:3,自引:1,他引:2
Subsequent welding requirement calls for high-quality laser cut surfaces in the laser cutting of bladed ring parts for aeroengines. This paper presents pulsed laser cutting of titanium alloy sheet and investigates the influences of laser cutting parameters on laser cut quality factors including heat-affected zone (HAZ), surface morphology and corrosion resistance. The thickness of HAZ lasers is studied in detail as a function of laser cutting parameters. For different assist gases the surface morphology and corrosion resistance show great differences. In comparison with air- and nitrogen-assisted laser cutting, argon-assisted laser cutting comes with unaffected surface quality and is suitable for laser cutting with subsequent welding requirement. 相似文献
3.
4.
5.
A method is described for detection of CO2 laser power variations which requires no optical detector. It is based on electric field changes near the laser tube induced by the laser power fluctuations within the optical cavity. This phenomenon called by us “antenna effect” is used for laser stabilization. A simple and inexpensive technique for CO2 laser power measurements, resonator adjustment, and for observation of the laser signature is described. 相似文献
6.
YUAN Xiao DING Guilin LIU Jingru LAU¨U Baida Julius Goldhar Physics Department Sichuan University Chengdu China Northwest Institute of Nuclear Technology P.O.Box Xi''''an China 《Chinese Journal of Lasers》2001,10(5):333-336
1 Introduction Inrecentyearstherehasbeenanintensiveeffortdirectedtowardtheproductionofshortpulse,high powerUVlasersystems .KrFlaser,withits~ 2nmbandwidth ,highelectrical to opticalconversionefficiencyanditsunbound groundstate ,isanattractivecandidateforthe… 相似文献
7.
新概念高能激光武器的研究与发展已有四十多年的历史。第一代高能激光武器主要采用连续波化学激光器,其输出功率可达百万瓦。第二代高能激光武器主要采用了波长更短的节能固体激光器件,其输出功率为100kW。与第一代高能化学激光武器采用超高能量直接烧毁杀伤目标不同,第二代高能固体激光武器寻求节能型杀伤方式,即以最小程度的破坏来实现致命杀伤的效果。随着高能激光武器的发展和实战部署,作为高能激光武器核心的高能激光系统总体性能参数(能量/功率、激光波形、光束质量、近场和远场的强度分布、光束指向稳定性、光谱和偏振特性等)的计量和测试显得尤为重要。文中围绕新概念高能激光武器的历史、研究现状和未来发展展开论述。高能激光武器系统的研制对强激光光学计量检测技术提出的新要求和挑战有助于推进强激光光学计量检测技术的发展。 相似文献
8.
F. Chen L. X. Yu X. L. Liu B. Q. Yao G. Li C. H. Zhang Y. Z. Wang Y. L. Ju 《Laser Physics》2012,22(1):91-94
In this paper, we present experimental results concerning on the laser characteristics of Tm:YAG laser and Tm: GdVO4 laser. At room temperature, the maximum output power of Tm:YAG laser and Tm:GdVO4 laser is 210 and 145 mW, respectively. High efficiency can be achieved for both lasers at room temperature. Nevertheless,
compared with Tm:GdVO4 laser, Tm:YAG laser can operate on single frequency with high power easily. As much as 60 mW of 2013.9 nm single-longitudinal-mode
(SLM) laser was achieved for Tm:YAG laser. For Tm:GdVO4 laser 51 mW of 1919.7 nm SLM laser was achieved. The SLM Tm:YAG laser is better for using as a seed laser for coherent wind
measurements and differential absorption LIDAR systems. 相似文献
9.
采用无模激光器发射波长为330 nm的激光激发多色激光导星,需要考虑脉冲激光重频率、激光带宽、激光初始光斑直径以及大气透过率对回波光子数的影响.通过数值模拟,计算了高斯光束的脉冲激光和连续激光激发多色激光导星在实际大气中后向辐射330 nm和2207 nm波长的回波光子数.数值计算结果表明,在垂直发射和接收的情况下,当到达大气中间层的激光能量为1 W时,连续激光能够获得更多的回波光子数,并且回波光子数几乎无起伏.对于脉冲激光,提高脉冲激光重频率达到50 kHz以上时,多色激光导星330 nm的回波光子数随脉冲重频率的增加趋于有限值;当大气能见度小于5 km且大气相干长度为12.8 cm时,大约需要34 W以上的激光发射能量,才能获得满足使用自然星全倾斜探测的330 nm回波光子数.对于连续激光,相同情况下,大约需要20 W以上的激光发射能量. 相似文献
10.
注入锁定TEA CO2激光器激光脉冲特性分析 总被引:1,自引:0,他引:1
本文在一般的TEACO2激光器的动力学方程的基础上,给出注入锁定情况下TEACO2激光器的动力学方程组,并进行数值计算,结果表明,TEACO2激光器注入锁定激光脉冲宽度比自由运转时的变宽了,脉冲峰值功率降低,而且激光脉冲产生的时间提前,这与实验规律相吻合。 相似文献
11.
本文描述CO激发器的发展及潜在应用。叙述工业用预冷气流激光器,气动激光器和外科用水冷管式激光器。概述三种类型的预电离TEA CO激光器及电子束控制CO激光器。最后介绍CO激光器选用的贵金属催化剂。 相似文献
12.
A.?A.?Ionin Yu.?M.?Klimachev A.?Yu.?Kozlov A.?A.?Kotkov O.?A.?Romanovskii L.?V.?Seleznev D.?V.?Sinitsyn O.?V.?Kharchenko
In the present work it is demonstrated that a wideband CO laser operating at fundamental and overtone vibrational transitions
is a promising source of laser radiation for remote laser sensing of the atmosphere. A compact slab RF-discharge CO laser
has been designed. The optimal operating conditions are determined for this CO laser. In experiments, the maximum average
output laser power was ∼12 W for lasing efficiency of ∼14%. Under fixed experimental conditions, stable lasing (with fluctuations
of the output laser characteristics ≤5%) was observed during more than one hour, which suggests that we first excited the
sealed-off mode of cryogenic slab RF-discharge CO laser. The frequency-selective mode was first obtained for this laser. Wavelengths
for sensing of nitrous oxide, nitrogen dioxide, methane, formaldehyde, and some other gases on near-ground propagation paths
are determined. Our experiments and calculations confirm that this CO laser is promising for laser gas analysis.
Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 11, pp. 76–83, November, 2008. 相似文献
13.
14.
The stability and reliability of probe laser is an important factor affecting the inspection of the phase transformation process of Si thin films during excimer laser crystallization using in-situ time-resolved optical measurements. The changes in 2D intensity profile, peak power density, and beam wander of the commonly used helium–neon (He–Ne) and diode laser are investigated experimentally. It is found that the peak power density of He–Ne laser is higher than that of diode laser, while the total power of He–Ne laser is lower than that of diode laser. Although the instability in the peak power density of He–Ne laser will increase with increasing the operation time, the beam stability of He–Ne laser is better than that of diode laser. For long-time operation (>24 h) of optical measurements, the diode laser is a good candidate of probe laser. Conversely, the diode laser is suitable for the short-time operation (<24 h) of optical measurements because the beam-wander is higher than that of He–Ne laser. 相似文献
15.
在长距离无线光通信中,接收点光功率密度与光束发散角平方呈反比关系,为了获得小的发散角和大的功率耦合效率,要求准直系统有较大的数值孔径(NA),但数值孔径过大会增加像差,因此合理设计功率耦合效率与准直系统的数值孔径就非常重要。该文对半导体激光器光束准直系统中功率耦合效率进行了研究,给出了半导体激光器光束功率耦合效率与k(孔径半径与孔径处等效光束半径之比)的关系表达式,并结合激光器光束准直系统,给出了半导体激光器光束功率耦合效率与准直系统数值孔径的关系表达式。该研究结论对于半导体激光器光束准直系统设计具有参考作用。 相似文献
16.
脉冲激光引起金属靶板层裂的阈值条件 总被引:5,自引:1,他引:4
本文考虑单脉冲激光作用于金属靶引起的应力波单次反射导致层裂的阈值条件,包括激光通量与应力波强度的定标关系、应力波传播时的衰减、入射波与反射波相互作用以及不同层裂判据的比较。本文结果指出,对于一定的激光通量和靶板厚度,只有一定范围内的激光脉宽才能造成层裂,最低激光通量则对应于最佳激光脉宽。本文的方法和结论也适合于飞片撞击造成的层裂现象。 相似文献
17.
18.
19.
本文配合KrF激光器的设计,对其动力学过程作了零维模拟计算,并与国内外实验结果进行了比较。通过模拟研究,对KrF激光器本征效率的提高、激光器对入射束流的要求以及对激光腔体的设计等都提出了很好的建议与简单实用的计算模式。 相似文献
20.
在惯性约束聚变研究中, 时标激光是对物理诊断数据进行分析的重要时间标尺, 而任意反射面速度干涉仪(VISAR)光源则是冲击波精密诊断必不可少的探针光源. 通过对物理需求的分析, 提出对时标激光与VISAR光源共用脉冲产生单元, 采用时分复用技术实现二者在同一台幅度调制器上的精密整形, 经1×2分束后再通过声光开关进行选择输出, 从而降低了系统造价, 便于集中控制. 采用了脉冲稳偏、高稳定空间放大、高精度温控谐波转换技术及可快速插拔精密复位的光纤耦合和传能技术, 实现了时标和VISAR光源脉冲的高稳定输出. 研制的时标激光系统可产生与主激光高精度同步的12路二倍频、4路三倍频时标信号, 为神光-III激光装置物理实验提供了重要的时间基准. 产生的VISAR光源脉冲在经过光纤系统和Nd: YAG棒状放大器后, 通过温控LBO晶体倍频, 然后经1 mm芯径的多模传能光纤传输至成像型VISAR系统, 为物理实验提供了单纵模、高亮度、可精密整形的脉冲激光. 系统已用于VISAR诊断物理实验, 获得了完整的冲击加载、减速的图像, 从而为冲击波调速及相关高压物理实验提供了可靠的技术手段. 相似文献