共查询到20条相似文献,搜索用时 15 毫秒
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Tan Jichun Wei Xiaofeng Cheng Zhe Yuan Xiaodong Liu Lirong Shi ZHiquan 《Chinese Journal of Lasers》1998,7(1):46-50
GeometricArangementwithMultiplicityofLaserBeamsinTargetAreaTANJichunWEIXiaofeng1)CHENGZheYUANXiaodong1)LIULirongSHIZhiquan(De... 相似文献
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In this paper,attention is focused on the intensity moments of the Hermite-Cosh-Gaussian (HChG) laser beams from the zero-order to the fourth-order.The frequently used parameters such as the power in bucket (PIB),the beam width,the curvature radius,the far field divergence,the M2-factor,the Rayleigh length and the kurtosis are calculated in terms of the intensity moments.Figures show the influence of the mode index and the decentered parameter,which are the critical parameters of the HChG beams.Moreover,the center of the gravity of the radiation field and the symmetry are discussed along with the propagation axis.Finally,the power fraction within the beam width defined by the second moments is illustrated with numerical method. 相似文献
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CHEN BaoZhen 《理论物理通讯》2000,33(4):521-524
A new analytic model for ATIspectra of He in circularly polarized laser is proposed.The model gives a way to describe the effects of the final state Coulomb interaction and the joint interaction of the atomic potential and laser field. The experimental spectra by Mohideen et al. can be quite well described. The peak intensity contradiction, which appeared in previous literatures, can be considerably eliminated. 相似文献
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1 Introduction Inrecentyears ,aninterestingsolutionofthe paraxialwaveequation ,knownastheHermite sinusoidal Gaussian (HSG )beams,hasbeenintroducedbyCaspersonandTovar[1,2 ] .AsoneofthespecialexampleinHSGfamily ,theHermite cosh Gaussian(HChG)beams′sfielddistributi… 相似文献
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提出了一种多参量调控角向偏振光束焦场强度和横向能流的方法.基于矢量衍射积分理论,数值模拟了非均匀螺旋相位和旋转对称振幅挡板调制下角向偏振光束的聚焦特性,讨论了螺旋相位结构和对称振幅挡板联合调制下,角向偏振光束焦场横向能流和偏振态的分布.结果表明:非均匀螺旋相位的引入改变了光场的聚焦特性,导致聚焦场重心产生了偏移;在偶数重旋转对称振幅挡板的联合调制下,焦场中出现了局部的椭圆偏振态和圆偏振态,且焦平面上出现了横向能流;通过调节螺旋相位,不仅可以实现焦场重心的特殊控制,还能进一步丰富焦场偏振态和横向能流分布.这种基于多参量调控焦场强度和能流分布的方法为实现操控特定区域的粒子提供了新的思路. 相似文献
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Tightly Focusing of Circularly Polarized Vortex Beams through a Uniaxial Birefringent Crystal 下载免费PDF全文
Under the approximation of small birefringence, the properties of circularly polarized vortex beams tightly focused through a uniaxial birefringent crystal are studied. With the proper combination of the topological charge and the birefringence, the small focus, the small bottle beam and the inverse c-shaped intensity profile can be obtained. The effects of the focal shift and the Strehl ratio on the birefringence are analysed. A relation between angular momentum (included spin and orbital) and topological Pancharatnam charge is also presented. 相似文献
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Optical forces acting on a micro-sphere were studied to corroborate the single-beam fiber optic trap. Transverse optical force acted to pull the micro-sphere back to the beam axis, but axial force always acted in the direction away from the optical fiber end because the laser beam from optical fiber could not be strongly focused. A stable two-dimensional optical trapping could be obtained by the weakly focused laser beam from the fiber end inserted at an angle. 相似文献
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Jean-François Bisson Akira Shirakawa Youhei Sato Yuri Senatsky Ken-Ichi Ueda 《Optical Review》2004,11(6):353-357
A Nd:YAG rod active element placed inside a resonator was pumped by the second harmonic radiation (the wavelength =0.532 m) of a Q-switched Nd:YAG laser diffracted at a circular aperture. Various distributions of pumping intensity in the Fresnel (near-field) region along the direction of the pump beam diffraction were produced. Inversion profiles with maxima or minima at the resonator axis were formed in the active element, depending on its distance from the circular aperture. Gain-switched operation of the Nd:YAG rod laser at =1.064 m is reported at the fundamental mode and also at the TEM01, TEM01* and other higher-order modes for different positions of the active element in the near-field region. Applications of such diffractive optical pumping for the concentration of the pumping radiation into the active media and for laser beam profling are discussed. © 2004 The Optical Society of Japan 相似文献
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部分偏振部分相干光光栅衍射场的偏振特性和角相关研究 总被引:1,自引:0,他引:1
为了研究部分偏振部分相干光光栅衍射场的衍射特性.利用部分偏振部分相干光的光束相干-偏振(BCP)矩阵,推导出了部分偏振部分相干光通过任意偏振光栅后,衍射场的偏振度及场中衍射级次角相关的一般解析表达式.以部分偏振的高斯-谢尔模型光束(PGSM)为例,数值分析了偏振光栅TE和TM波的复振幅透过率、入射光束的光学参量对衍射场偏振度和场中各衍射级次的角相关的影响.计算结果表明,部分相干光透过偏振光栅后的其衍射光场是一非均匀、周期变化的部分偏振相干光场;场中对称级次的角相干值对应相等,且随衍射级次序数的增大而缓慢递减至零. 相似文献
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U. Schramm M. Bussmann D. Habs M. Steck T. Kühl K. Beckert P. Beller B. Franzke F. Nolden G. Saathoff S. Reinhardt S. Karpuk 《Hyperfine Interactions》2005,162(1-4):181-188
We report on the first laser cooling of a bunched beam of multiply charged ions performed at the ESR (GSI) at a beam energy of GeV. Moderate bunching provided a force counteracting the decelerating laser force of one counterpropagating laser beam.
This versatile type of laser cooling lead to longitudinally space-charge dominated beams with an unprecedented momentum spread
of . Concerning the beam energy and charge state of the ion, the experiment depicts an important intermediate step from the established
field of laser cooling of ion beams at low energies toward the unique laser cooling scheme proposed for relativistic beams
of highly charged heavy ions at SIS 300 (FAIR).
Funded by the German BMBF under contract number 06ML183. 相似文献
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A semiconductor laser diode with circularly symmetric waveguide is proposed, its property is studied by scalar finite-difference time-domain method (SFD-TDM). The results show coupling loss between the semiconductor laser diode and single mode fiber is reduced effectively, the minimum coupling loss is 0.7 dB. 相似文献
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In the paraxial optics approximation, we have studied the transformation of a simple Gaussian beam of light obliquely incident on an isotropic lens for the case where the axis of the beam and the principal optical axis of the lens are crossed straight lines. The data obtained are compared with the corresponding results for the case where the axes of the beam and lens are coplanar. 相似文献
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基于分析激光二极管光束传输特性,运用厄米-高斯光束描述其远场分布.将自聚焦透镜用于激光二极管的光束整形,用2阶传输矩阵描述自聚焦透镜.运用Collins衍射积分公式,分析了LD光束在自聚焦透镜中传输场分布的解析表达式.在此基础上,数值计算了一种LD光束在自聚焦透镜中场分布.该模型结构简单,可用于分析光束传输特性和设计光束整形系统. 相似文献
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We studied the optical forces acting on a sphere in order to corroborate the three-dimensional optical trapping by the laser beams from optical fiber ends inserted at an angle. From these investigations, we verified that there was only one stable point of equilibrium located below the beam-crossing point. Furthermore, we could reveal that employing microlenses in a dual-beam trap enhanced the trapping stability and increased the trapping volume. 相似文献
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K. Wies C. Geppert K. Blaum K. Brück H.-J. Kluge S. Schwarz K. Wendt 《Hyperfine Interactions》2005,162(1-4):29-38
A new type of resonance ionization laser ion source (RILIS) is presently being developed and tested at the off-line mass separator
at Mainz University for future use at on-line exotic rare isotopes production facilities. For highest isobaric selectivity,
this RILIS approach decouples the evaporation and ionization process. A further advantage is the generation of full temporal
control of the resulting high quality ion beam. These facts are realized by a combination of atomizer – ion repeller – ion
cooler and trap, which is operated together with a state-of-the-art, all solid state laser system. The principle and performance
of this laser ion source trap (LIST) system are discussed applying simulation studies for the repeller-trap combination and
first measurements for characterization. 相似文献