School of Electrical & Electronic Engineering, Nanyang Technological University, Nanyang Avenue, 639798. Singapore.
Opt Lett. 2011 Aug 15;36(16):3287-9. doi: 10.1364/OL.36.003287.
We demonstrate an experimental result that shows the phase singularity of surface plasmon waves generated by the direct transform of optical vortices at normal incidence focused on a structureless metal surface. The near-field two-dimensional intensity distribution near the focal plane is experimentally examined by using near-field scanning optical microscopy and shows a good agreement with the finite-difference time-domain simulation result. The experimental realization demonstrates a potential of the proposed excitation scheme to be reconfigured locally with advantages over structures milled into optically thick metallic films for plasmonics applications involving plasmonic vortices.
我们展示了一个实验结果，表明在无结构金属表面上聚焦的正常入射光的光学涡旋的直接变换产生的表面等离激元波的相位奇点。通过近场扫描光学显微镜实验研究了近场焦平面附近的二维强度分布，并与有限差分时域模拟结果吻合良好。实验实现证明了所提出的激励方案具有局部可重构的潜力，与在光学厚金属薄膜中铣削结构相比，在涉及等离子体涡旋的等离子体应用中具有优势。
