Free electrons moving in an optical standing wave field feel the ponderomotive potential, acting as a refractive-index medium in electron optics. Emerging technologies involving this potential have been proposed and realized in electron microscopy, such as electron phase-contrast imaging using a laser standing wave in an optical enhancement cavity. However, the interaction between electrons and a cylindrically distributed optical field has not been investigated despite its suitability for electron-optical imaging systems. In this study, we theoretically show that the divergence and convergence forces are provided by tightly focused cylindrically polarized light beams. The radially and azimuthally polarized beams with an annular profile are focused using a high-numerical-aperture optical lens. The intensity distributions at the focus function are concave and convex electron round lenses, respectively. The convex lens formed by the azimuthally polarized beam possesses negative (opposite sign) spherical aberration compared with conventional electron round lenses created by electrodes and magnetic coils. This remarkable result will contribute to the innovative design of electron-optical imaging systems and advances in matter-wave optics.

中文翻译：

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通过紧密聚焦的圆柱偏振光束具有负球面像差的电子圆透镜

在光学驻波场中运动的自由电子感受到有质动力势，在电子光学中充当折射率介质。已经在电子显微镜中提出并实现了涉及这种潜力的新兴技术，例如在光学增强腔中使用激光驻波的电子相衬成像。然而，尽管其适用于电子光学成像系统，但尚未研究电子与圆柱形分布光场之间的相互作用。在这项研究中，我们从理论上表明发散力和会聚力是由紧密聚焦的圆柱偏振光束提供的。具有环形轮廓的径向和方位角偏振光束使用高数值孔径光学透镜聚焦。聚焦函数处的强度分布分别是凹电子圆透镜和凸电子圆透镜。与由电极和磁线圈产生的传统电子圆形透镜相比，由方位角偏振光束形成的凸透镜具有负（相反符号）球面像差。这一非凡的成果将有助于电子光学成像系统的创新设计和物质波光学的进步。