Optical forces on resonant metallic cylinders near supertransmitting slits illuminated by a photonic nanojet

摘要

We analyze optical forces exerted on 2D metallic particles, i. e. infinite cylinders, near a subwavelength slit in supertransmission regime and illuminated by a photonic nanojet, comparing the cases in which their plasmonic resonances are or are not excited. Furthermore, we show that illuminating the slit by means of a photonic nanojet even enhances the optical forces at the exit of the aperture by a factor between 3 and 10 compared to the case of the slit directly illuminated by the Gaussian beam. Also, the presence of the slit can change the pulling nature of the force that the direct illumination by the nanojet exerts on the small metallic particle in resonance, becoming repulsive at certain lateral positions of this latter.