方位角偏振光聚焦光斑的研究  

Study on the focusing spot of azimuthally polarized light

作　　者：王伟[1] 吴建光[1] 李勇 刘义[1] 李海金[1] 

机构地区：[1]安徽工业大学数理科学与工程学院,安徽马鞍山243032

出　　处：《光电子．激光》2015年第4期805-811,共7页Journal of Optoelectronics·Laser

基　　金：国家自然科学基金(11204004;11204005;51202005);安徽工业大学教学研究(2011jg54)资助项目

摘　　要：对方位偏振平面波、高斯光束、贝塞尔-高斯光束和双环拉盖尔-高斯光束的聚焦特性进行了理论计算,分析了物镜数值孔径和截断因子对焦平面上光强分布、中心暗斑半径的影响,以及加入中心遮拦光阑对焦深和中心暗斑半径的影响。研究发现,4种模式光束形成的聚焦场中心暗斑半径随着数值孔径的增大,单调减小,其大小与数值孔径成反比,与波长成正比;截断因子的改变仅影响高斯光束和贝塞尔-高斯光束中心暗斑半径的大小,对其旁瓣强度的影响较小,但会使得双环拉盖尔-高斯光束焦场光强重新分配,能够形成等光强的双亮环结构;加入中心光阑能够减小焦平面上中心暗斑半径并增大焦深。The focusing properties of plane wave, Gaussian beam, Bessel-Gaussian beam and double-ring Laguerre-Gaussian beam are studied using theoretical calculation method. The rules of focal intensity distribution and radius of center dark area are analyzed with the variations of numerical aperture and truncation parameter. Through theoretic analysis and calculation, the rules of using central obscuration aperture to increase depth of focus and reduce the radius of central dark area are also analyzed. Resear- ches find that the radii of central dark area formed by 4 kinds of light beams in the focal plane are mono- tonically decreasing, which are inversely proportional to the numerical aperture and proportional to the wavelength. The change of truncation factor has more influence on the radius of central dark area while has little effect on the sidelobe intensity which is formed by Gaussian beam or Bessel-Gaussian beam. Optical intensity distribution in focal plane formed by double-ring azimuthally Laguerre Gauss beam can be redistributed with the variety of truncation factor. A double ring structure which has equal intensity can be formed in the focal plane. Using the central obscuration aperture, the radius of central dark area in focal plane can be reduced and the depth of focus can be increased. Research results may have quite im- portant applications for azimuthally polarized light.

关 键 词：物理光学 方位偏振光 聚焦 空心光束 

分 类 号：O436[机械工程—光学工程]