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1.
A tensor form for describing approximately the elliptical aperture function is defined that can be expanded into a finite sum of complex Gaussian functions. An analytical propagation formula of elliptical Gaussian beams through nonsymmetric and paraxial optical systems with an elliptical aperture is obtained by using tensor method. A simple numerical example is given to illustrate for its applications. 相似文献
2.
Tensor ABCD law for partially coherent twisted anisotropic Gaussian-Schell model beams 总被引:7,自引:0,他引:7
A 4 x 4 complex curvature tensor M>(-1) is introduced to describe partially coherent anisotropic Gaussian-Schell model (GSM) beams. An analytical propagation formula for the cross-spectral density of partially coherent anisotropic GSM beams is derived. The propagation law of M(-1) that is also derived may be called partially coherent tensor ABCD law. The analytical formulas presented here are useful in treating the propagation and transformation of partially coherent anisotropic GSM beams, which include previous results for completely coherent Gaussian beams as special cases. 相似文献
3.
The symmetrizing transformation of coherent general astigmatic Gaussian beams is analysed by the tensor ABCD law. It is shown in this paper that a nonorthogonal astigmatic Gaussian beam (with rotation) can be transformed into a rotationally symmetric one by the combination of four cylindrical lenses. A simple example is given. 相似文献
4.
Based on the tensor method, an analytical formula for hollow Gaussian beams (HGBs) generated by a triangular prism has been derived, and the propagation properties have been studied. It is shown that hollow elliptical Gaussian beams (HEGBs) can be obtained in the near field after the prism, and that the eccentricity of the output beam is affected by parameters such as the incidence angle, refractive index of the prism and the order of the HGB. It shows that by using a triangular prism one can conveniently obtain HEGBs. 相似文献
5.
Z. Tong O. Korotkova Y. Cai H. T. Eyyuboglu Y. Baykal 《Applied physics. B, Lasers and optics》2009,97(4):849-857
With the help of the generalized Huygens–Fresnel principle and the tensor approach for electromagnetic stochastic beams we
investigate the behavior of their two-point spatial correlation properties on interaction with a laser resonator. In particular,
the evolution of the degree of coherence, of the degree of cross-polarization and of the intensity correlations (at one and
two points in space) is analyzed for typical beams and cavities. The theory is illustrated by numerical curves pertaining
to various correlation properties of typical electromagnetic Gaussian Schell-model beams. 相似文献
6.
The propagation of phase-locked and non-phase-locked laser array beams of radial and rectangular symmetries in a turbulent
atmosphere are investigated based on the extended Huygens–Fresnel integral. The beamlet used in our paper for constructing
the laser array beams is of elliptical Gaussian mode. Analytical formulae for the average irradiance of phase-locked and non-phase-locked
radial and rectangular laser array beams are derived through vector integration and tensor operation. The irradiance properties
of these laser array beams in a turbulent atmosphere are studied numerically. It is found that both phase-locked and non-phase-locked
radial and rectangular laser array beams eventually become circular Gaussian beams in a turbulent atmosphere, which is much
different from their propagation properties in free space. The propagation properties are closely related to the parameters
of laser array beams and the structure constant of the turbulent atmosphere.
PACS 42.25.Bs; 41.85.Ew; 42.68.Ay 相似文献
7.
从傍轴条件下光束轨道角动量的基本理论出发,根据高阶椭圆厄密–高斯光束的光场分布,运用张量方法,对高阶椭圆厄密-高斯光束轨道角动量的密度分布进行了理论分析,得到了求解该密度分布的计算公式,并在给定参量条件下作了数值模拟.进一步对光束中每个光子携带的平均轨道角动量进行了计算,发现其值随着椭圆厄密-高斯光束阶次的增大而增大,表明高阶椭圆厄密-高斯光束能够比椭圆高斯光束或拉盖尔-高斯光束提供高得多的轨道角动量. 相似文献
8.
A generalized diffraction integral formula for stochastic electromagnetic beams propagating through an optical system in turbulent
atmosphere is derived with the help of tensor method. Some analyses are illustrated by a numerical example relating to changes
in the average intensity and the degree of polarization of an electromagnetic Gaussian Schell-model beam propagating through
a double-lenses system. It is shown that the optical system has strong influence on the propagation properties of the beam.
The method used in this paper can be widely applied to the propagation of astigmatic beams through an optical system in turbulent
atmosphere. 相似文献
9.
《Optics Communications》2004,229(1-6):93-98
Analytical transform formulae for partially polarized Gaussian Schell-model (GSM) beams propagating in dispersive and absorbing media are derived by use of a new tensor method. Using the derived formulae, we studied the polarization and irradiance distribution properties of partially polarized GSM beams in dispersive and absorbing media. The results show that the dispersive and absorbing media has strong influence on the polarization and irradiance distribution of partially polarized GSM beams. The polarization and irradiance distribution of partially polarized GSM beams in dispersive and absorbing media are also closely related to the initial coherence and the source spectral width of partially polarized GSM beams. The propagation properties of an nonpolarized GSM beam and partially polarized GSM beams are compared and discussed. Our method provides a convenient way to treat the propagation of partially polarized GSM beams in different linear medium. 相似文献
10.
TransformationofpulsedGaussianbeamsinafourdimensiondomainLINQiang;WANGShaomin(DepartmentofPhysics,HangzhouUniversity,Hangzhou... 相似文献
11.
12.
Changes in the spectrum of twist anisotropic Gaussian Schell-model beams propagating through turbulent atmosphere 总被引:1,自引:0,他引:1
Based on the extended Huygens-Fresnel principle, the spectrum of twist anisotropic Gaussian Schell-model (TAGSM) beams propagating through turbulent atmosphere is derived analytically by using the partially coherent complex curvature tensor. The relative spectral shift of TAGSM beams propagating through turbulent atmosphere is closely related with the strength of atmospheric turbulence, the beam’s parameter and the radial coordinate. The on-axis spectral shift of TAGSM beams propagating through turbulent atmosphere changes from blue shift to red shift with the increasing of the propagation distance z, and at a certain propagation distance z, there exists a rapid transition of the spectrum at the critical position rc. 相似文献
13.
Fractional Fourier transform for partially coherent beam in spatial-frequency domain 总被引:1,自引:0,他引:1 下载免费PDF全文
By using Fourier transform and the tensor analysis method, the fractional Fourier transform (FRT) in the spatial-frequency domain for partially coherent beams is derived. Based on the FRT in the spatial-frequency domain, an analytical transform formula is derived for a partially coherent twisted anisotropic Gaussian-Schell model (GSM) beam passing through the FRT system. The connections between the FRT formula and the generalized diffraction integral formulae for partially coherent beams through an aligned optical system and a misaligned optical system in the spatial-frequency domain are discussed, separately. By using the derived formula, the intensity distribution of partially coherent twisted anisotropic GSM beams in the FRT plane are studied in detail. The formula derived provide a convenient tool for analysing and calculating the FRTs of the partially coherent beams in spatial-frequency domain. 相似文献
14.
Serkan Sahin 《Optics Communications》2010,283(22):4512-4518
An active bistatic LIDAR system operating through atmospheric turbulence is considered. Illumination field is assumed to be an electromagnetic Gaussian-Schell model beam. Target surface is modeled as a combination of isotropic phase screen governed by Gaussian statistics, to account for its roughness, and a Gaussian lens to account for its size and radius of curvature. With the help of a recently developed tensor method for propagation of stochastic electromagnetic beams through ABCD systems and random media we examine the evolution of states of coherence and polarization of the beam. In the case of unresolved flat (planar) target we show that by comparing coherence and polarization properties of the illumination beam and of the return beam it is possible to predict the typical roughness of the target surface. 相似文献
15.
Xinyue Du 《Optics Communications》2006,265(2):418-424
Using tensor method, a new kind of light beams named elliptical cosh-Gaussian beam (EChGB) is introduced in this paper. An analytical propagation expression for the EChGB passing through axially nonsymmetrical ABCD optical systems is derived by using vector integration. The derived formula is easily reduced to the propagation formula of a fundamental Gaussian beam and that of a cosh-Gaussian beam passing through optical systems. Some numerical simulations are illustrated for the propagation properties of EChGBs through the nonsymmetrical optical transforming systems, and further extensions are pointed out. 相似文献
16.
空心锥状双高斯光束传输特性研究 总被引:1,自引:1,他引:0
建立了空心锥状双高斯光束的模型.在空心高斯光束模型的基础上,由初始光场的光强分布,利用柱坐标下的柯林斯公式,导出了空心锥状双高斯光束经过傍轴光学系统的解析传输变换式由传输变换式计算分析了空心锥状双高斯光束在自由空问的可控传输特性,及在1,10和60 m的截面光环的光强分布.用KNbO3双轴晶体进行实验,获得了空心锥状双高斯光束,外锥折射的锥角等于入射光会聚角.实验表明,当空心光束处于锥状发射状态时,空心光束的光环内黑斑面积随传输距离的增加而增加,实验结果与模型吻合较好.该研究为进一步设计制备基于空心锥状舣高斯光束的新型激光元件提供了理论依据和设计参量. 相似文献
17.
Analytic expressions and computed examples are given to elucidate the coherence and polarization properties of Stokes beams, i.e. beams formed by superposition of a completely unpolarized and a completely polarized electromagnetic Gaussian Schell-model beam. We found that superposition of such two beams cannot form a Stokes beam with a constant state of polarization on propagation. An additional constraint on the source plane parameters of the two Gaussian Schell-model beams is proposed. The resultant Stokes beam with a constant state of polarization on propagation is found to be a Gaussian Schell-model beam with the same variances as the two constituent Gaussian Schell-model beams. However, the modulus of the Gaussian intensity distributions across the source planes of these beams may be different. 相似文献
18.
H. T. Eyyubo?lu 《Applied physics. B, Lasers and optics》2010,98(1):203-210
As an extension of our previous study, the area scintillation aspects of Bessel Gaussian and modified Bessel Gaussian beams
of zeroth order are investigated. The analysis is carried out on the basis of equal source sizes and equal source powers.
It is found that, when compared on equal source size basis, modified Bessel Gaussian beams always have less area scintillations
than a Gaussian beam, while Bessel Gaussian beams exhibit more area scintillations. Comparison on equal source power basis,
however, removes the advantage of modified Bessel Gaussian beams, that is, their area scintillations become nearly the same
as those of the Gaussian beam. On the other hand, for the case of equal source powers, Bessel Gaussian beams with larger width
parameters continue to have higher area scintillations than the Gaussian beam. We provide graphical illustrations for profiles
of equal source size beams, equal source power beams and the curves to aid the selection of equal source power beams. 相似文献
19.
20.
双曲余弦高斯光束通过有光阑限制的ABCD光学系统的传输 总被引:8,自引:0,他引:8
对双曲余弦高斯光束通过有硬边光阑的一阶ABCD光学系统的传输进行了研究,采用将矩形域函数表示为复高斯函数叠加的技巧,推导出了解析的传输公式,在特殊情况下,该公式简化为在无光阑情况下的传输公式,对双曲余弦高斯光束通过有光阑限制的薄膜镜聚焦进行了数值计算,计算结果与直接由柯林斯(Collins)公式所得结果一致,且此解析方法便于进行物理分析,可节约大量机时。 相似文献