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根据电磁辐射理论和矢量光场积分理论,研究了矢量光束聚焦场特性与聚焦透镜数值孔径之间的关系。在透镜焦场区设定电偶极子阵列和磁偶极子阵列,收集其辐射场并反向聚焦,通过调控与优化偶极子阵列参数,反演不同数值孔径透镜下的聚焦光场,获得了聚焦光针场、三维衍射受限光管场随透镜数值孔径的变化规律。研究结果表明,随着数值孔径的减小,光针场的纵向分量纯度、边缘斜率以及光针长度递减,半峰全宽递增,光管场依旧保持纯方位角偏振分布,且中空区域的半峰全宽递增。研究结果对在不同数值孔径下矢量光束聚焦的应用研究具有重要意义。 相似文献
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作为光波最重要的本征物理属性之一,光场偏振态在研究光与物质相互作用中占有重要地位。矢量光场的波前调控为其聚焦场提供了更加复杂、更加灵活可控的振幅、相位以及偏振态分布,丰富了光与物质相互作用的手段,为材料表征提供了传统线偏振、圆偏振光场所不可替代的研究方法,具有重要的物理意义和实际应用价值。本文将综述矢量光场最新的研究进展,详细介绍矢量光场的偏振态特性、产生方法,以及紧聚焦轴对称矢量光场波前调控在远场小尺度光斑的产生、磁光记录、单分子/颗粒取向探测、任意三维偏振态的产生、高密度数据存储、信息加密以及矢量光场波前重构等方面的重要应用。 相似文献
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柱矢量光束的紧聚焦在光学微操纵、光学存储、激光微加工、超分辨率成像和粒子加速等领域发挥着重要作用。亚波长光栅平凹透镜对柱矢量光束的紧聚焦的能力仍有提升空间,本文利用闪耀结构将光的能量从零级转移并集中到-1级,对亚波长光栅平凹透镜的聚焦性能进行优化。提高了透镜的衍射效率,增强了焦场的能量。通过调整高斯径向偏振光的形状参数,改变入射光振幅及入射区域半径实现对焦场能量的动态调控。进一步地,调控柱矢量光束的偏振组分能够直接有效地横向调制焦场,获得多样化形貌的焦斑。本文的优化手段对于其他光栅透镜也具有参考意义,该研究结果在超分辨率成像以及光场调控等领域具有潜在的应用价值。 相似文献
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用空间滤波器改善光管式光学均匀器的性能 总被引:1,自引:1,他引:0
本文报道了一种用空间滤波改善光管式光学均匀性的技术,该技术使用空间滤波器滤除入射光束中光场突变部分,提高了光管式学均匀器的均匀性能。 相似文献
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基于圆极化波入射条件下的高效同极化反射超表面实现了对圆极化反射波相位的自由调控, 设计了一维圆极化波反射聚焦超表面. 在中心频率f=16 GHz附近, 右旋圆极化平面波入射时, 反射波聚焦于焦距L=200 mm的实焦点; 左旋圆极化波入射时, 反射波近似聚焦于焦距L=-200 mm的虚焦点. 仿真计算得到聚焦波束的波束宽度、焦深. 结果表明, 这种圆极化反射聚焦超表面具有很好的聚焦效果, 同时具有长焦深和宽带特性. 相似文献
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偏振是光的基本属性之一,也是光学课程教学中的重点内容。但由于课时限制等原因,光学课程对于光的偏振介绍比较简单,内容也局限于老旧内容。随着光学的发展,矢量偏振光束由于其独特的特性已经被广泛的研究和应用,因此,在光学课程中引入偏振发展的前沿知识,有助于学生探索新的光学发展领域,从而激发他们的学习兴趣,为推动教研融合作出积极贡献。本文以矢量偏振光束通过高数值孔径物镜的衍射为例,基于矢量衍射理论和MATLAB模拟仿真展示偏振态对光场传播过程和聚焦光场的影响。首先根据矢量衍射理论推导了聚焦场分布积分表示;然后借助MATLAB仿真给出了矢量偏振光束入射情况下聚焦光场分布;最后通过与常见的线偏振光和圆偏振光对比,对矢量偏振光束聚焦场分布进行了分析和总结。 相似文献
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用矢量衍射方法分析了线偏振光入射到带有三环位相型光瞳滤波器的高数值孔径物镜时,焦点的轴向和横向光强分布.数值模拟结果表明,高数值孔径物镜聚焦时需同时考虑光强的轴向和横向分布.通过加入三环位相光瞳滤波器,在实现横向超分辨的同时实现了光学系统轴向焦深扩展和轴向光强分布平坦化,并且位相调制深度变化时,会出现轴向焦移现象.对三环位相光瞳滤波器结构进行了优化,得出了优化结果.
关键词:
光学超分辨
扩展焦深
位相型光瞳滤波器
矢量衍射方法 相似文献
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轴对称矢量光束是一种空间非均匀偏振光束, 中心光强为零, 经物镜聚焦后能在焦点附近产生空间场分量. 在高变迹系数光学系统成像情况下, 与线偏光、圆偏光相比, 径向偏振光与光瞳滤波技术及图像复原技术结合, 能获得较小焦斑, 提高横向分辨力. 介绍了轴对称矢量光束的特性, 基于电偶极子辐射模型和矢量衍射理论研究了轴对称矢量光束经高数值孔径物镜聚焦后的特性, 系统介绍了基于轴对称矢量光束实现光斑紧聚焦的几种方法, 并简述了轴对称矢量光束在差动共焦超分辨成像领域的研究设想.
关键词:
差动共焦显微技术
紧聚焦
光瞳滤波
轴对称矢量光束 相似文献
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Bing Gu Yang Pan Guanghao Rui Danfeng Xu Qiwen Zhan Yiping Cui 《Applied physics. B, Lasers and optics》2014,117(3):915-926
We investigate the focusing property and the polarization evolution characteristics of hybridly polarized vector fields in the focal region. Three types of hybridly polarized vector fields, namely azimuthal-variant hybridly polarized vector field, radial-variant hybridly polarized vector field, and spatial-variant hybridly polarized vector field, are experimentally generated. The intensity distributions and the polarization evolution of these hybridly polarized vector fields focused under low numerical aperture (NA) are experimentally studied and good agreements with the numerical simulations are obtained. The three-dimensional (3D) state of polarization and the field distribution within the focal volume of these hybridly polarized vector fields under high-NA focusing are studied numerically. The optical curl force on Rayleigh particles induced by tightly focused hybridly polarized vector fields, which results in the orbital motion of trapped particles, is analyzed. Simulation results demonstrate that polarization-only modulation provided by the hybridly polarized vector field allows one to control both the intensity distribution and 3D elliptical polarization in the focal region, which may find interesting applications in particle trapping, manipulation, and orientation analysis. 相似文献
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Sharper focus for a radially polarized light beam 总被引:5,自引:0,他引:5
We experimentally demonstrate for the first time that a radially polarized field can be focused to a spot size significantly smaller [0.16(1)lambda(2)] than for linear polarization (0.26lambda(2)). The effect of the vector properties of light is shown by a comparison of the focal intensity distribution for radially and azimuthally polarized input fields. For strong focusing, a radially polarized field leads to a longitudinal electric field component at the focus which is sharp and centered at the optical axis. The relative contribution of this component is enhanced by using an annular aperture. 相似文献
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The longitudinal optical field is a peculiar physical phenomenon that is always involved with the domain of near-field optics. Due to its extraordinary properties, it has recently attracted increasing attention in research and application. In this work, the longitudinal fields generated by the evanescent illumination of tightly focused, different polarized hollow beams are investigated. The focused light fields are numerically simulated according to vector diffraction theory, and their vector analysis is also carried out. The longitudinal fields on the focal plane are demonstrated experimentally using tip-enhanced scanning near-field microscopy. The simulation and experimental results show that the tightly focused radially polarized beam is suited to generating a stronger and purer longitudinal optical field at the focus. 相似文献
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Tight focusing of spatially variant vector optical fields with elliptical symmetry of linear polarization 总被引:1,自引:0,他引:1
We study the tight-focusing properties of spatially variant vector optical fields with elliptical symmetry of linear polarization. We found the eccentricity of the incident polarized light to be an important parameter providing an additional degree of freedom assisting in controlling the field properties at the focus and allowing matching of the field distribution at the focus to the specific application. Applications of these space-variant polarized beams vary from lithography and optical storage to particle beam trapping and material processing. 相似文献
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Tight focusing of axially symmetric polarized vortex beams is studied numerically based on vector diffraction theory. The mathematical expressions for the focused fields are derived. Simulation results show that the focused fields and phase distributions at focus are largely influenced by both the polarization order and topological charge of the incident beams. Moreover, focal spots with flat-topped or tightly-focused patterns can be flexibly achieved by carefully choosing the polar- ization order and the topological charge, which confirms the potential of such beams in wide applications, such as optical tweezers, laser printing, lithography, and material processing. 相似文献
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We demonstrate that the optical bottle-shaped fields can be controllably generated by the focused spatial-variant linearly polarized vector beams. Based on the vectorial Rayleigh–Sommerfeld formulas under the paraxial approximation, we present theoretically the analytical expression for the focused field of the vector beam and predict the evolution of the sate of polarization (SoP) in the focal region. Experimentally, we observe the vector bottle-shaped field that is in agreement with the numerical simulations. In particular, we validate that both the SoP and the size of the optical bottle field are manipulated easily by varying the azimuthal topological charge and the radial mode index. 相似文献
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A phase/amplitude mask on the aperture of an imaging system results in a pupil function that is multiplicative with the lens function, resulting in a morphological transformation of the imaging wavefront. It was shown that such amplitude and phase functions can be implemented using polarization masks, with the advantage that the phase and amplitude can be controlled in real time and in some cases, independently of each other. The phase and amplitude variation over the mask can be controlled either by changing the polarization of the mask or by changing the input beam parameters. Wavefront tailoring using polarization-masked apertures is therefore feasible and may be utilized for focal shift and partial aberration compensation. For complete compensation of aberration, the phase distribution over the mask should be conjugate to that of the phase error of the aberrant wavefront, which necessitates the use of a continuously variable polarization mask. Since such a mask is difficult to implement, we have considered polarizing masks consisting of discrete polarized zones on the lens aperture, leading to polarization phase steps on the exit pupil of the imaging system. The simulation results presented in this paper show that effects of focal shift, partial compensation of primary spherical aberration and astigmatism can indeed be achieved by the proper use of polarization masked apertures. 相似文献