共查询到19条相似文献,搜索用时 109 毫秒
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2010年是激光发明50周年.文章首先回顾了50年前激光的发明,说明基础科学创新的重大引领作用.接着概述了50年来激光领域的重大进展,包括激光器技术及其应用研究的进展;举例说明了激光应用对基础科学的反馈和推动作用;归纳了高能激光器的几个发展趋势;分析了激光的军事应用及其科学技术支撑.最后给出了激光50年发展史的4点启示和今后的3类发展方向. 相似文献
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2010年是激光发明50周年.文章首先回顾了50年前激光的发明,说明基础科学创新的重大引领作用.接着概述了50年来激光领域的重大进展,包括激光器技术及其应用研究的进展;举例说明了激光应用对基础科学的反馈和推动作用;归纳了高能激光器的几个发展趋势;分析了激光的军事应用及其科学技术支撑.最后给出了激光50年发展史的4点启示和今后的3类发展方向. 相似文献
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激光聚变靶物理研究用激光强率I随空间的变化来反映激光能量的沉积。目前激光靶物理研究使用的激光能量沉积方程在临界面处发散,讨论了造成这一非物理结果的原因,给出了合理的激光强度方程,并讨论了新旧两种激光强度方程对激光吸收的影响。 相似文献
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激光聚变的理论和实验研究是一项综合性的应用研究.为了弄清激光靶耦合的物理规律,作各种分解研究是很有必要的.在激光间接驱动内爆研究中,要求激光以某一角度进入黑洞靶中与靶相互作用.作为一个分解问题,本文在几何光路近似和一维密度分布的假定下对钕玻璃激光与金(Au)平面靶耦合的吸收作了自洽这这的数值计算,通过结果分析给出了激光吸收效率随激光入射角、强度和波长的变化规律,同时还给出激光吸收区电子温度、X射线转换效率随激光入射角的变化规律.模型计算值与国内外已发表的理论和实验结果作了比较,其定性趋势和定量结果都不同程
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高功率固体激光是激光聚变、高能量密度物理与前沿基础科学研究必需的实验手段。上世纪六七十年代,老一辈科学家王淦昌、王大珩、邓锡铭、于敏等人以敏锐的科学洞察力与超前的战略眼光,开创了中国激光聚变研究的宏伟工程,为中国高功率固体激光技术的长远发展注入了强劲的东风。中国工程物理研究院(简称中物院)作为激光聚变研究的总体单位,联合中国科学院等国内优势单位,在国家强有力的支持下,推动与组织了中国高功率固体激光技术与装置研制的快速发展。中物院激光聚变研究中心作为高功率固体激光技术研发的总体单位之一,敢于担当、勇于创新,团结协作,坚持三十余载,实现了中国高功率固体激光技术研发历程中的两次“突破”,即突破新一代高功率钕玻璃激光技术,相继研制成功了亚洲规模最大、技术先进的神光-Ⅲ原型装置和神光-Ⅲ激光装置;突破百太瓦超短超强激光关键技术,建成了国内首台输出能力高达200 TW的SILEX-Ⅰ超短超强脉冲激光装置。两次“突破”,不但有力地支撑了中国激光聚变与相关基础科学研究的高速发展,同时实现了中国高功率固体激光技术发展由“望尘莫及”到“望其项背”的跨越,奠定了由“望其项背”到与美、法先进国家“三足鼎立”的坚实基础。 相似文献
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Thrust enhancement via gel-type liquid confinement of laser ablation of solid metal propellant 总被引:1,自引:0,他引:1
Soojin Choi Tae-hee Han Ardian B. Gojani Jack J. Yoh 《Applied Physics A: Materials Science & Processing》2010,98(1):147-151
Laser propulsion has been developed as a suitable small thruster technology for the attitude control of micro and nano class
satellites. Laser-based thrusters meet the satellite design criteria for being of light weight and cost effective, because
they do not require fuel storing and oxidizer for combustion. Also, thrust control by laser propulsion is achieved fairly
easy. In this paper, we consider the confinement of plasma expansion by a gel-type liquid material, which results in the enhancement
of the thrust for propulsion. We also present our attempts to resolve some known issues regarding laser ablation of solid
and liquid targets. The level of thrust is quantified via the momentum coupling coefficient, which was experimentally measured
using a ballistic pendulum system. We have discovered that the laser ablation confinement by the gel-type medium results in
2.3 times more enhanced driving force as compared to the water confinement. A proof of performance is demonstrated for using
gel-type material for generating propulsion, and material characterization for optimal thrust performance is presented. 相似文献
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脉冲激光烧蚀推进技术具有比冲高和推力可精确控制的特点,既可用于发射有效载荷也可用于星载动力,甚至可用小行星表面物质作为推进剂使其偏转轨道,因此,在航天领域得到越来越多关注。围绕激光单级入轨发射、同步轨道和火星轨道运输;激光微推力器用于航天器姿轨控,以及激光与电组合推进;激光烧蚀操控cm级空间碎片的轨道,以及激光烧蚀操控较大尺寸碎片的姿态;激光烧蚀偏转小行星轨道等方面,对脉冲激光烧蚀推进技术在航天领域研究现状和进展,进行了系统全面地归纳和总结,并对激光平均功率、波长、脉宽和推进剂选材等关键问题,进行了详细分析。 相似文献
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Romain Fardel Lukas Urech Thomas Lippert Claude Phipps James M. Fitz-Gerald Alexander Wokaun 《Applied Physics A: Materials Science & Processing》2009,94(3):657-665
Laser plasma thrusters are a new kind of propulsion system for small satellites, and work with the thrust created by the laser
ablation of a target. Liquid polymer solutions are very promising fuels for such systems, provided that no splashing of the
target occurs, because ejection of droplets strongly decreases the performances of the system. We have investigated the nanosecond
infrared laser ablation of glycidyl azide polymer solutions containing carbon nanoparticles as absorber. Shadowgraphy imaging
revealed two cases, namely splashing regime and solid-like behavior. The transition between both regimes depends on the viscosity
of the solution and on the laser fluence, and is explained by the recoil force acting on the target. Appropriate conditions
to avoid splashing were identified, showing that this liquid polymer solution is a suitable fuel for laser plasma thrusters. 相似文献
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针对抛物形喷管与圆柱形喷管相组合的带延长圆柱形喷管激光推力器模型,通过求解含激光能量源项的流体力学方程组,计算得到了不同单脉冲激光能量条件下3种构形参数对冲量耦合系数和推力的影响。结果显示带延长圆柱形喷管可获得高于600N/MW的冲量耦合系数,同时表明冲量耦合系数随圆柱喷管长度的增加而增大并趋于饱和,圆柱喷管饱和长度与激光能量呈线性关系。冲量耦合系数随抛物形喷管张角的增大先增大后减小,对于总长度为100mm的喷管,半张角在33°左右时取得最大值且受激光能量的影响很小。冲量耦合系数随点火位置的增大也存在最大值,最大值对应的点火位置与激光能量成线性关系。 相似文献
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针对抛物形喷管与圆柱形喷管相组合的带延长圆柱形喷管激光推力器模型,通过求解含激光能量源项的流体力学方程组,计算得到了不同单脉冲激光能量条件下3种构形参数对冲量耦合系数和推力的影响。结果显示带延长圆柱形喷管可获得高于600 N/MW的冲量耦合系数,同时表明冲量耦合系数随圆柱喷管长度的增加而增大并趋于饱和,圆柱喷管饱和长度与激光能量呈线性关系。冲量耦合系数随抛物形喷管张角的增大先增大后减小,对于总长度为100 mm的喷管,半张角在33°左右时取得最大值且受激光能量的影响很小。冲量耦合系数随点火位置的增大也存在最大值,最大值对应的点火位置与激光能量成线性关系。 相似文献
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Investigation of laser via formation technology for the manufacturing of high density substrates 总被引:1,自引:0,他引:1
Fabrication of micro-vias is one of the critical processes in manufacturing high-density printed circuit boards. The conventional mechanical drilling technique becomes expensive for vias smaller than 200 μm in diameter due to the frequent breakage of the drill bits and machine downtime. The inability to produce blind vias renders the mechanical drilling method of limited use in providing vertical interconnections needed for multi-layer boards. Laser micro-drilling has emerged as one of the most feasible technologies for forming micro-vias. It offers greater resolution over the mechanical technique and is capable of producing vias well below 70 μm, consistently. The feasibility of being able to laser drill depends on the laser characteristics such as wavelength, energy density and pulse shape of the laser beam on the one hand, and on the type, structure configuration and thickness of the PCB substrate on the other hand. As most of the PCB materials have finite absorption characteristics with respect to the laser wavelength, only certain laser types are compatible with the common substrate materials. Laser via-drilling can either be a serial process with one via drilled at a time, or a mask imaging process with many vias drilled simultaneously. In this paper, the issues involved in the laser micro-drilling of PCB vias, including beam characteristics and processing mechanisms, for different substrates are investigated. A brief comparison with the other two emerging technologies, i.e. photo-vias and plasma etching is also discussed. 相似文献
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超连续谱激光指的是当泵浦激光穿过特殊光波导时,一系列的非线性效应引起入射激光束的光谱展宽,从而输出宽光谱激光束。随着超快激光和光子晶体光纤技术的发展,利用超短脉冲在光子晶体光纤中的传播链产生相干的且亮度高的超连续谱激光成为了一种理想的白光源。自从超连续谱激光源投入应用以来,其应用领域越来越广。尤其在生物医学的细胞、血液等样品分析当中,荧光光谱学、流式细胞仪、共焦显微、光学相干层析等技术都是强有力的分析工具,在采用这些先进技术的科学仪器中,超连续谱激光源成为了一种主要光学部件。首先对超连续谱激光源的国际研究进展作了详细介绍,然后对超连续激光光谱技术在显微成像、流式细胞仪、荧光寿命成像显微、荧光共振能量转移、光学相干层析、共焦显微生物医学分析等生物医学领域中的发展及应用作了综合阐述。对超连续激光光谱技术在非接触式血液制品鉴别的需求、方案及研究进展进行了重点论述,包括覆盖400~2 000 nm光谱范围的光纤化轻型超连续谱激光光源研究;采用超连续谱激光光谱方法探索不同物种血液的种属特征;根据大数据的血液样品光谱特征元数据库分析建立数学模型,利用数学模型实现对血液样品种属光谱学判定;血液鉴别光谱分析便携式整机系统研发等。对超连续激光光谱技术在生物医学领域的应用前景作了展望。 相似文献