共查询到20条相似文献,搜索用时 62 毫秒
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像散光束的光束参数与光强二阶矩的关系 总被引:5,自引:3,他引:2
采用光束的二阶强度矩的方法讨论三维像散光束的光束特性。通过计算像散光束在自由空间、球面光学系统中的传输特性以及坐标系旋转时的变换特性 ,给出了光束的束腰位置、束腰半径、瑞利长度、有效波面曲率半径、近场和远场的方位角、光束的光束参数积等参数与光强二阶矩之间的关系。 相似文献
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从1+1维强非局域模型出发,讨论了偏离束腰入射的高斯光束在非局域非线性介质中的传输 特性,得到了精确的解析解.结果表明,在聚焦介质中偏离束腰入射时,不论入射功率多大 ,光束束宽将发生周期性波动,光孤子不复存在,这与从高斯光束束腰入射的情况有本质的 不同;入射功率决定了光束平均束宽的大小,入射位置决定了光束初始的演化趋势.比较了在入射位置相同的条件下,聚焦介质、散焦介质和线性均匀介质中光束的演化.给出了“空 间啁啾”的定义,偏离束腰入射的物理本质是光束的不同入射位置对应不同的初始空间啁啾 .空间啁啾的概念,
关键词:
非局域非线性介质
空间光孤子
高斯光束 相似文献
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轴对称非球面透镜光轴共轴度的测量研究 总被引:1,自引:0,他引:1
介绍了一种轴对称非球面透镜的光轴共轴度的测量方法。激光管发出的光束经束腰变换透镜入射到被测透镜的非球面表面,由CCD摄像头接收非球面的反射激光光斑,CCD的光敏面位于反射激光光束的束腰位置;调整被测透镜位置,直到激光束腰中心位置不随被测非球面透镜的旋转而变化,这说明被测透镜的非球面对称轴与机械旋转轴重合;再利用球面偏心测量原理检测被测透镜球面一面的偏心量,即可以求得被测非球面透镜的光轴共轴度。该测量方法的误差小于20″。该方法适用于判定非球面透镜和非球面反射镜是否合格,以及调整非球面透镜的制造工艺。 相似文献
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《中国光学与应用光学文摘》2006,(3)
TH703 2006032021激光光学系统设计中球差对像方束腰的影响=Effect ofspherical aberration on the i mage beam waist in the designof laser optical system[刊,中]/江恒(华中科技大学光电子工程系.湖北,武汉(430074)) ,杨坤涛∥激光与红外.—2006 ,36(2) .—128-130针对激光光学系统设计中存在的球差对高斯光束像方束腰半径的影响进行了详细的讨论,并给出了具体关系。同时以曲线的形式分析了当物方束腰的位置和光学系统焦距变化时,由球差引起的像方束腰半径变化量也随之改变。最后通过激光羽烟衰减测试系统中聚光光学系统的设计实例,说… 相似文献
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通过三个多丝剖面监测器测量漂移空间三点处的束流剖面,对HIRFL加速器横向束流发射度(_(12)C~(+6)束)进行了测量。文章给出了测量综合结果,并着重计算分析了“三剖面”法发射度测量中,三个探测器之间的距离、测量区间束腰的位置和束腰的大小对测量误差的影响,最后给出了测量最佳条件。 相似文献
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双光子吸收碱金属蒸汽激光器(TPAL)在基础研究和国防工程中有重要的应用前景,近些年来已成为激光领域研究热点之一,但TPAL还缺少相关的理论模型。因此,本文基于碱金属原子的双光子吸收能级跃迁过程构建速率方程,并建立了TPAL理论模型,研究了单波长泵浦双光子吸收铷蒸汽激光器(Rb-TPAL)的工作特性,分析了泵浦光束腰位置、蒸汽池温度以及泵浦功率对Rb-TPAL蓝光输出特性的影响。结果表明,通过优化泵浦光束腰位置和蒸汽池温度,在高功率泵浦情况下,Rb-TPAL可获得高功率蓝光激光输出。 相似文献
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Ensheng Fu Quirong Shen Yingfeng Li Bing Wang Lei Chen Yuzhi Wang Zhijiang Wang 《Chinese Journal of Lasers》1992,1(2):165-171
The diagnostic system for two dimension(2-D)intensity distribution of laserbeam is a measuring instrument for many parameters of laser beam.2-D intensity distributionplot of laser beam is obtained by the two dimension scanning mirror which is controlled by amicrocomputer to scan the laser beam on a detector.Many parameters of laser beam such asthe isointensity distribution plot,the beam diameter,the beam waist diameter,the laser pow-er,the diverge angle and the beam brightness,are given by means of the microcomputer pro-cessing the data measured.Theoretical analysis of beam parameter transform is given. 相似文献
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Yu. E. Geints A. A. Zemlyanov 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2009,55(3):745-754
Focused propagation of high-power femtosecond laser radiation in air is
considered. Based on numerical solution of the nonlinear Schr?dinger
equation for complex envelope of light wave electric field, evolution of the
beam effective radius is studied. The dependence of the effective (rms) size
of a focal spot and the maximally achievable intensity of laser radiation at
focal waist on the initial pulse power is established. It is shown that
focal spot of tightly focused intensive ultrashort laser radiation can
change its size during the pulse passage through the beam waist. This is the
consequence of pulse intensity clamping in region of beam focusing caused by
gas photoionization and plasma producing. This may prevent laser intensity
from its further growth in the focal region and arrest the transversal
compression of the beam in the linear focus as a whole. 相似文献
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Wenjie Xie Siu-Chung Tam Yee-Loy Lam Hongru Yang Jianhui Gu Gang Zhao Wilson Tan 《Optics & Laser Technology》1999,31(8):555-558
Based on space-dependent rate equation, the lowest threshold input power for diode end-pumped solid state lasers is obtained for pump spot size wp → 0. However, when the pump beam waist is decreased, the far-field half-angle increases due to the same beam quality, which will influence the match between the pump volume and mode volume. Most importantly, when the pump beam waist is decreased, the temperature and temperature gradient in the laser rod would be very high due to the resulting heat, which would cause material distortion, variation of refractive index, instability of laser resonator etc. We analyze the temperature distributions with different pump beam sizes and conclude that the condition wp ≈ w0 (the radius of the laser beam at the laser rod) is often taken as a rough guide to the optimum case. 相似文献
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In-vacuum propagation of a polychromatic Gaussian beam emitted by a dispersive laser resonator and its passage through thin plates are studied under following assumptions: optical fields are stationary and plane-polarized, the paraxial wave equation is valid for each monochromatic component of the beam, the waist position and the Rayleigh range depend on wavelength and diffraction edge effects are negligible. Mathematical expressions for beam radius, divergence, beam parameter product and beam propagation factor are obtained. The use of thin plates for waist position achromatization is analyzed. 相似文献
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高功率激光光束特性对激光加工的影响 总被引:4,自引:0,他引:4
决定光与物质相互作用的激光束的波长、入射角、偏振特性以及时间和空间特性是激光材料加工的主要光束特性。激光束的光束质量是其空间特性的量化反映。通过对两种不同激光加工系统输出激光光束质量进行测量和计算,根据多模激光束的聚焦理论,以及对激光深熔焊接实验结果的分析,研究了光束质量对深熔焊接焊缝成形的影响。结果表明,光束质量对聚焦光束的焦斑、聚焦角和焦深的影响不仅体现了激光源的可聚焦性,而且也标志了激光源的可加工能力,这是聚焦系统和焦点位置在选择过程中应该考虑的重要因素。 相似文献
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Yaling Yin 《Optics Communications》2008,281(22):5511-5514
We propose a simple optical device to convert a Gaussian laser beam into a neat semi-Gaussian laser beam without any diffraction fringe by using a spatial light modulator and a thin, sharp blade, and numerically calculate the diffracted, relative intensity distributions of both the semi-Gaussian laser field and the semi-Gaussian, pseudo-thermal light. We also study the dependence of the border width of the semi-Gaussian beam on the waist of the Gaussian beam. Our study shows that the proposed scheme can be used to cancel all diffraction fringes from both the straight edge of the blade and a finite lens aperture in all the planes vertical to the z axis and obtain a neat semi-Gaussian beam without any diffraction fringe, and find that the border width wB of the generated semi-Gaussian beam is not dependent on the waist of the incident Gaussian beam. 相似文献