Dutta Jhuma, Ramakrishna S Anantha
Department of Physics, Indian Institute of Technology Kanpur, Kanpur 208016, India.
Nanotechnology. 2015 May 22;26(20):205301. doi: 10.1088/0957-4484/26/20/205301. Epub 2015 Apr 27.
Gratings with slanted plasmonic nanocolumns of silver (Ag) on top fabricated by physical vapor deposition at large oblique angles on predefined gratings show unique plasmonic properties. These aligned nanocolumns with high-aspect ratios can be uniformly re-oriented to any desired angle of slant by ion beam irradiation. A focused ion beam (FIB) has been used as the ion source here. The plastic deformation of the nanocolumns arises due to defect formation caused by the energetic ions and can enable the complete tuning of the photonic and plasmonic properties of the grating through the slant angle. The reorientation can be uniformly carried over large areas of 0.2 mm(2) with the FIB and the diffraction patterns from the reoriented grating show large changes in the diffraction efficiencies. Electromagnetic simulations of the grating structures reveal large changes in the photonic properties with the slant angle such as diffraction efficiencies and the electromagnetic near fields.
通过在预定义光栅上以大倾斜角进行物理气相沉积在顶部制备的具有倾斜银（Ag）等离子体纳米柱的光栅展现出独特的等离子体特性。这些具有高纵横比的排列纳米柱可以通过离子束辐照均匀地重新定向到任何所需的倾斜角度。这里使用聚焦离子束（FIB）作为离子源。纳米柱的塑性变形是由于高能离子导致的缺陷形成而产生的，并且可以通过倾斜角实现对光栅的光子和等离子体特性的完全调谐。使用FIB可以在0.2平方毫米的大面积上均匀地进行重新定向，并且重新定向后的光栅的衍射图案显示出衍射效率的巨大变化。光栅结构的电磁模拟揭示了随着倾斜角光子特性的巨大变化，如衍射效率和电磁近场。
