Feng Di
J Opt Soc Am A Opt Image Sci Vis. 2014 Sep 1;31(9):2070-4. doi: 10.1364/JOSAA.31.002070.
By using a gold bowtie nanoantenna at the focal plane of a plasmonic Fresnel zone plate lens, we numerically demonstrate that the focused beam spot can be strongly confined in a three-dimensional (3D) region, which means the focal spot will have high axial resolution as well as high lateral resolution. According to the antenna's resonance spectrum, the Fresnel zone plate lens is designed at the resonance wavelength of the antenna to get the right diffractive efficiency, and then the antenna will be positioned at the focal plane, so the 3D confined focal spot can be achieved with much higher intensity and much smaller spot size along both axial and transverse directions than that of a lens without using antennas.
通过在等离子体菲涅耳波带片透镜的焦平面处使用金领结纳米天线，我们通过数值模拟证明聚焦光束光斑可以在三维（3D）区域中被强烈限制，这意味着焦斑将具有高轴向分辨率以及高横向分辨率。根据天线的共振光谱，在天线的共振波长处设计菲涅耳波带片透镜以获得合适的衍射效率，然后将天线放置在焦平面处，因此与不使用天线的透镜相比，可实现具有更高强度以及沿轴向和横向方向上更小光斑尺寸的三维受限焦斑。
