Force distribution inside the spoof surface plasmon polariton waveguide

The Maxwell stress tensor for the field inside a spoof surface plasmon polariton (SSPP) waveguide and the electromagnetic force distribution acting on a dielectric particle are investigated. We show that, for particles made of material with the dielectric function slightly different from that of the medium filling the waveguide, the force distribution is fully described by the SSPP field in the absence of the particle. The spatial profile of the field strongly depends on the relation between the operating frequency and the SSPP resonance frequency. We show that varying the characteristic frequencies introduces a switching effect, when the direction of the force along the waveguide axis changes ( from toward the grooves to away from them). We propose a pumping mechanism based on force acting on a small particle inside the SSPP waveguide. (C) 2018 Optical Society of America.