排序方式: 共有98条查询结果,搜索用时 15 毫秒
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光学元件上存在的缺陷会对传输光束产生局域振幅和位相调制. 基于衍射理论模型和分步傅里叶算法,模拟分析了高斯光束经过表面有缺陷的非线性介质的传输过程中于介质内及从介质出射后在自由空气的传输特性, 并详细研究了在厚介质前表面有缺陷的情况下,介质中和自由空气中的光强分布演化规律. 研究表明,介质厚度越长、介质的非线性折射率越大,光束整体聚焦越厉害, 聚焦点离介质后表面越近.光束受调制点的位置离中心越近,光束分裂成丝产生的局部光强越大, 且介质表面存在缺陷将使通过的光束在介质后表面处产生一个很大的光强, 相位调制型缺陷产生的这一光强点比振幅调制型缺陷产生的光强点更强. 相似文献
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在近轴光束近似条件下,采用交叉谱密度传输公式推导了 部分相干涡旋光束传输一段距离后观测平面上交叉谱密度矩阵元的解析表达式, 在此基础上对观测平面上的光强分布进行了分析.研究表明, 和完全相干涡旋光束不同,部分相干涡旋光束传输后光斑中心点的光强会逐渐凸现出来, 随着传输距离的增加,观测平面上的光强会逐渐演变为类似高斯型分布的特性. 这种演变规律与源平面上光源的拓扑电荷数和相干长度有关, 在其他参数不变的情况下,拓扑电荷数越小,相干长度越短, 演变为高斯型光斑的速度越快.最后针对一阶部分相干高斯涡旋光束, 通过观测平面上光强极值研究,对光斑随传输距离演变的过程进行了详细的分析, 在理论上对这种演变规律给出了严格的证明. 相似文献
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Propagation properties of stochastic electromagnetic double-vortex beams in a turbulent atmosphere 下载免费PDF全文
Based on the extended Huygens-Fresnel principle,we study the propagation properties of stochastic electromagnetic double-vortex beams in a turbulent atmosphere.The result shows that the spreading of partially coherent double-vortex beams can be smaller than that of fully coherent ones.The degree of polarization of this kind of beam will experience change,which is dependent on the degree of polarization of the source plane,the atmospheric turbulence,topological charge,and the spatial coherence.The results may have applications in space optical communication. 相似文献
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Tight Focusing of Radially and Azimuthally Polarized Vortex Beams through a Dielectric Interface 总被引:1,自引:0,他引:1 下载免费PDF全文
Based on vectorial Debye theory, tight focusing of radially and azimuthally polarized vortex beams passing through a dielectric interface are studied. The intensity distribution in the focal region is illustrated by numerical calculations. We show the influence of numerical-aperture (NA) on the full-width at half maximum (FWHM) of the focal spot or the focal hole. It has been found that compared with the azimuthally polarized Besse~Gaussian (BG) beams, the longitudinal component in the z direction of the radially polarized BG beams has no influence on the FWHM of the focal spot and hole, but enhances the total light intensity. 相似文献
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部分相干光经柱面球差透镜聚焦所产生的焦移 总被引:7,自引:7,他引:0
利用Collins公式得出光强均匀部分相干光经柱面球差透镜聚焦后的轴上光强分布,并通过数值模拟的方法研究了入射光的菲涅耳数、相干度和透镜的球差对轴上点光强分布的影响.结果显示,当菲涅耳数较小、空间相干度较小的部分相干光经无球差透镜聚焦时,轴上点光强分布会产生焦移现象,而当部分相干光被球差透镜聚焦时,也会有焦移现象产生. 相似文献
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Spectral anomalies of polychromatic, spatially coherent light diffracted by an annular aperture in the far field 总被引:2,自引:0,他引:2
In recent years, a great deal of attention has been paid to the structure of wave fields in the neighborhood of points where the field amplitude has zero value[1-3]. At such points the phase of fields is singular. It has been known that in the neighborhood of the singular points, the wave fields exhibit a rather complex structure, for example, dislocations and optical vortices. Studies of phenomena associated with phase singularities have gradually devel- oped into a new branch of physical opt… 相似文献
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根据惠更斯-菲涅耳(Hugens-Fresnel)衍射积分,推导出高斯-斯克尔模型光束二阶相关函数经过光学系统的传输公式.引入与高斯光束类似的q参数.证明了高斯-斯克尔模型的q参数亦满足ABCD变换定律. 相似文献