Manipulation of field enhancement using tapered nanobumps with circular polarization

E. H. Khoo, I. Ahmed, and E. P. Li
Tapered nanobumps are placed on the circumference of optical vortex to manipulate the field amplitude using circular polarized light. Tapered nanobump produces stronger field enhancement due to higher charge density at the tapered end. The geometrical parameters of the tapered nanobumps are optimized to achieve highest field enhancement. The electric field is enhanced or diminished by illuminating with left or right circular polarized lightwave. Additional nanobumps are added to provide field enhancement at different parts of the vortex. This setup can be used to control the position of nanoparticles for analysis, and is useful for sensing and catalysis applications.
DOI