Formation of SPP vortex field and its application in multi-particle manipulation

The concept of interference in classical optics is applied to the generation of Surface Plasmon Polariton (SPP) vortex array fields. The simultaneous manipulation of multiple particles by laterally shifting the SPP vortex field has been numerically verified.

(A) relation between incident light beam with the nano-scale structure for generating SPP vortex field. (B) the resultant SPP vortex field. (C)(D) the recorded trajectories of two particles that controlled by the SPP vortex field.

Can SPP (vortex) fields be dynamically and optically controlled and be used to particle manipulations?

I asked myself this question, and the question inspired me to conduct this research.

Starting from forming a controllable SPP vortex field:

Four coherent laser beams are simultaneously focusing on a four-slit nano-structure to form a SPP vortex field. In particular, with our design, the result SPP vortex field can be dynamically controlled/shifted by adjusting the phase relationship between four incident beams. This opens up the possibility of using the SPP vortex field to manipulate multiple particles.

Next, manipulating multiple particles by the optically controllable SPP vortex field

The feasibility of simultaneous manipulation of two particles at the same time with the result SPP vortex field is verified by numerical simulation. This study is supposed to benefit SPP-related studies, such as: plasmonic dichroic splitter, unidirectional launching, tunable directional excitation, plasmonic structured illumination microscopy ,plasmonic splitter, and etc. The detail of this study can be found in the published paper, Opt. Express 26(15), 19123.