Efficient nano-tweezers via a silver plasmonic bowtie notch with curved grooves

Localized surface plasmon resonance (LSPR) with a sharp field gradient and extremely strong field intensity is very attractive for near-field optical nano-tweezers manipulating tiny bio-objects with sizes ranging from sub-10 nm to micrometers. To lower the power consumption of optical trapping and improve the accessibility of LSPR for the targets, we propose and study a plasmonic bowtie notch design with assisted periodic curved grooves. By generating and coupling extra surface plasmon polariton waves into the LSPR, the presented design herein can significantly reduce the required power consumption in experiments for stably trapping single and multiple polystyrene spheres. We believe the idea and results presented in this paper would be helpful in realizing highly efficient nano-tweezers in the plasmonic circuit on-chip.