On chip optical tractor beam by surface plasmon polariton

Optical Sorting of a Plasmonic or Dielectric or Chiral Mie Object Using a Single Metasurface

“…The interference field (generated from the superposition of these electromagnetic surface waves) was employed as an incident beam to optically manipulate the illuminated scatterers. Since such dual SPP energized nonparaxial beams remove discontinuity points [32] in the interference field patterns, manipulation distances and thus the possibilities of obtaining successful sorting regions are enhanced. The formation of a continuous interference field pattern over the substrate along the "y" direction as demonstrated by Figure 2b justifies the fact that the proposed on-chip setup suppresses multiple reflections and creates an optimal environment for effective optical manipulations.…”

“…According to past research works on optical tractor beam, direct interaction of either magnetic or electric poles always results in positive optical forces on dielectric particles whereas interferences due to induced poles are responsible for emergence of recoil forces. [32] Consequently, pushing force arises when force contributions from F direct interaction exceed those from F interference .…”

“…[25] Recent developments in metasurfaces have enabled us to gain better control over wavefronts, light-matter and spin-orbit interactions. [26] In addition, applications of these improved metamaterials in lateral trapping and longitudinal separation of metal nanoparticles (using metalens), [27] photon sorting, [28,29] generating complex plasmonic fields, [30] vortex beam arrays, [31] optical tractor beams, [32] etc., have garnered widespread attention amongst researchers of the modern era. Furthermore, employing metasurfaces and plasmonic structures in spin-dependent optics allows us to manipulate both surface waves and far field.…”

“…Designs possessing such arrangements of nanoscale unit cells are area efficient, suppress multiple reflections, increase coupling efficiency and manipulation distances. [32] Past research works involving plasmonics have successfully identified the existences of nonconservative optical pulling forces for dipolar (mostly "Rayleigh" ranged) dielectric particle (using linearly polarized plane wave) in [37] and demonstration of optical trapping for Mie sized plasmonic nanostructures (using the incidence of a radially polarized (RP) beam) in. [38] Our proposed metasurface-scatterer system enables exertion of completely different optical force for distinct separately placed Mie object.…”