Nanoparticle trapping by counter-surface plasmon polariton lens

A counter-surface plasmon polariton lens (CSPPL) is proposed to perform stable nanoparticle trapping by providing up to 120k(b)T optical potential depth. The optical potential depth is related to the incident angle and phase difference of the light incident on two gratings of CSPPL. The depth of optical potential can be manipulated with negligible displacement by the incident angle less than 20 degrees. Both the depth and the center position of the optical potential well can be manipulated by the incident phase difference. The study of stable and manipulatable optical potential on the CSPPL promotes the inte-gration of optical tweezers.