On-chip continuous position control of phase singularities in nanoscale.

Abstract

In this paper, continuous position control of plasmonic phase singularities on a metal-air interface is achieved based on the misaligned coupling between the optical axis of vortex beam and nano ring plasmonic lens. The formula of surface plasmon polaritons field distribution in this case is derived. The offset distance and direction between the optical axis of the vortex beam and the center of the nano ring is used to control the distance and the angular distribution of the phase singularities in nanoscale, respectively. This can promote the accurate positioning of phase singularities in practical applications and provide a deeper understanding of the misaligned coupling between vortex beams and nano ring plasmonic lens.