Optical Arbitrary Transporting Based on Au Plasmonic Structure by Changing the Polarization Directions

Optical tweezers, an important technique of particle manipulation, play an important role in the micro-and nano-fields. In this paper, with the method of FDTD, the optical field distributions under three plasmonic structures with different arrangements of Au cylinder and elliptical cylinder have been researched we find that the electric field intensity will show the strongest localized plasmonic resonant when the long and short axis of elliptical cylinder is adjacent. Furthermore, the force exerted on the particles is also the strongest. Then, a combined structure for particle transporting has been proposed on the basis of above analysis. With the rotation of polarization directions, hot spots will also rotate around the Au structure, and further trapped particles will be arbitrarily transported in a 2D scheme. Our research result provides a new theoretical support and practical method for the development of particle transport technology and we believe that this research is of great help and significance in promoting the further development of optical tweezers technology in the micro and nano fields.