共查询到20条相似文献,搜索用时 15 毫秒
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Based on the vector angular-spectrum and the complex Gaussian expansion of the aperture function, the structure of an apertured hollow Gaussian beam in the far field is given in a integral form. In virtue of the method of stationary phase approximation, the analytical vectorial structures are derived. Starting from the analytical expressions, the propagation properties of apertured hollow Gaussian beams with different order in the far field are illustrated graphically. In addition, the influence of the truncation parameter on far field distribution is studied detailedly. This research can shed light on the further understanding of the vectorial property of an apertured hollow Gaussian beam. 相似文献
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Restoration of Decentered Gaussian Beam with the Combination of a Lens and a Gaussian Aperture 总被引:1,自引:0,他引:1
1 Introduction TheGaussianbeamisthefundamentalshapeofthelaserwithaspherical mirrorresonatorandwidelyusedtodescribeasinglemodelaser.Intheparaxialapproximation ,thedistributionofcomplexamplitudeofitremainsunchangedwhenitundergoestheFouriertransformorthe… 相似文献
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The modified ray-optics method is used to analyze the coupling efficiency from a Gaussian beam to a rectangular multimode embedded strip waveguide. It is convenient for analyzing the case of a simple waveguide structure because of reduced computation time. The conditions for determining which optical rays can be coupled into the waveguide to become the waveguiding modes, as well as the effective receiving area of the waveguide, are derived in this work. The data obtained by this method are compared with those calculated by the well-known overlap integral theorem and Marcatili's models for investigating the validity of the modified ray-optics method. 相似文献
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Abstract The modified ray-optics method is used to analyze the coupling efficiency from a Gaussian beam to a rectangular multimode embedded strip waveguide. It is convenient for analyzing the case of a simple waveguide structure because of reduced computation time. The conditions for determining which optical rays can be coupled into the waveguide to become the waveguiding modes, as well as the effective receiving area of the waveguide, are derived in this work. The data obtained by this method are compared with those calculated by the well-known overlap integral theorem and Marcatili's models for investigating the validity of the modified ray-optics method. 相似文献
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A method that uses the quadrant photodiode has been shown to be relatively inexpensive and robust in measuring Gaussian laser beam diameters in two axes. This approach requires neither component rotation nor precision alignment, and it facilitates integration of Gaussian laser beam diameter measurement with laser beam tracking in instruments. The physical gap between sensors in the quadrant photodiode, however, limits laser beam diameter measurements to those in the millimeter range. Here, we describe a modified approach to measure Gaussian laser beam diameters that are significantly smaller. 相似文献
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The circular Gaussian beam shape has been simulated by numerical evaluation on beam shape based on z-scan method through beam radius. This method is useful in many studies such as z-scan experiments. The validity of the relation between peak and valley separation in close aperture data and the diffraction length of the beam has been investigated by this method for some real cases. The results are in good agreement with the experimental studies. 相似文献
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研究了一维(1D)线阵离轴高斯光束通过湍流大气的传输特性,推导出了其光强传输方程. 研究表明,1D线阵离轴高斯光束通过湍流大气传输经历了三个阶段,即在近场其光强分布为类似于入射光的锯齿状分布,随着传输距离的增加逐渐变为平顶分布,最后在远场成为类高斯分布. 湍流的增强会使光束传输经历三阶段的进程加快. 并且,湍流使得不同子光束数的1D线阵离轴高斯光束的归一化光强分布相接近. 此外,子光束数越多的1D线阵离轴高斯光束受到湍流的影响越小;1D线阵离轴高斯光束较高斯光束受到湍流的影响要小.
关键词:
一维(1D)线阵离轴高斯光束
湍流大气
传输特性 相似文献
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环形光束的锥形衍射效应对于微粒的操控具有重要的应用价值.本文建立了环状高斯光束的锥形衍射模型,并基于Berry理论给出了线偏振态下环形光束锥形衍射出射光场的计算公式.理论仿真了环状光锥形衍射出射光场的偏振特性,得出环光锥形衍射出射光场的内、外亮环具有相互正交的偏振分布特性.搭建了线偏振态下环状高斯光锥形衍射的实验系统,实验验证了出射光场的偏振特性.针对环形光束锥形衍射出射光场具备的偏振特性,设计了一种组合偏振片,理论和实验研究了该组合偏振片对环光锥形衍射出射光场的调控.结果表明,随着组合偏振片方位角的变化,锥形衍射出射光场的内、外环强度发生周期性的变化. 相似文献
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PU Jixiong 《Chinese Journal of Lasers》2001,10(3):228-232
1 Introduction Recentlytherehasbeenconsiderableinterestindesignandanalysisofthediffractiveaxiconsthatproduceafocalsegmentwithnearlyuniformopticalintensityalongthesystemaxiswithinaspecifiedregionbehindtheelement[1~1 2 ] .Thisisduetotheirunusualpropertiesa… 相似文献
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A method for the measurement of the spatial distribution of birefringence, caused by intense femtosecond laser pulses in condensed plasma, is presented for the case of a Gaussian laser beam. For that only two light intensities are to be measured on the probe beam in a polariscope. 相似文献
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The propagation formulae of elliptical Gaussian beam through misaligned optical systems in spatial domain and spatial-frequency domain are investigated analytically by using tensor method. The derived formulae provide a powerful tool for treating the propagation and transformation of elliptical Gaussian beam through misaligned optical systems. As an application example, the propagation properties of elliptical Gaussian beam through a misaligned thin lens are illustrated. 相似文献
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The propagation of elliptical Gaussian beam passing through paraxial optical systems with aperture is investigated analytically by using tensor method. The approximate formula for propagation of elliptical Gaussian beam through hard apertured optical systems is derived based on the fact that the circ function can be expanded into a finite sum of complex Gaussian functions. The derived formula provides a convenient tool for treating the propagation and transformation of elliptical Gaussian beam through apertured optical systems. As an application example, the propagation properties of elliptical Gaussian beam through apertured fractional Fourier systems are discussed. 相似文献
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Based on the vectorial structure of electromagnetic beam and the
method of stationary phase, the analytical structure of Hermite
Gaussian beam in far field is presented. The structural energy flux
distributions are also investigated in the far field. The structural
pictures of some Hermite Gaussian beams are depicted in the far
field. As the structure of Hermite Gaussian beam is dominated by the
transverse mode numbers and the initial transverse Gaussian half
width, it is more complex than that of Gaussian beam. The ratios of
the structural energy fluxes to the whole energy flux are independent
of the transverse mode numbers and the initial transverse Gaussian
half width.
The present research reveals the internal vectorial structure of Hermite Gaussian beam from other viewpoint.\ 相似文献