【摘要】 扫描近场光学显微镜突破了传统远场光学的衍射极限 ,能够获得超高光学分辨率。亚波长尺寸的小孔作为扫描近场光学显微镜中常用的金属膜光纤探针的简化模型。研究光透过小孔后的近场分布特性 ,对理解和分析探针在近场成像中的作用十分重要。采用时域有限差分 (FDTD)方法研究了无限大理想导体屏上纳米小孔的近场分布 ,计算结果表明 ,入射偏振光从小孔出射后发生了退极化 ,即出射光含有与入射光偏振方向垂直的电场分量。文中详细分析了小孔的近场分布特征与退极化之间的关系 ,研究了小孔的形状以及入射光偏振态对近场分布的影响更多还原

【Abstract】 The optical near field distribution of nanometric apertures was investigated using the finite difference time domain (FDTD) method. The result reveals that the polarized incident wave becomes depolarized after passing through the aperture. The wave has two electric field components with the polarization direction perpendicular to that of the incident one. The relationship between the optical near field distribution characteristics and depolarization are discussed and analyzed in detail. In addition, the influences of aperture shape and polarization direction of the incident wave on the optical near field distribution are investigated.更多还原