tuning of plasmonic nanofocusing with non-linear metallic helical nanocone

Plasmonic nanofocusing plays important role for the efficient conversion and manipulation of optical radiation on the nanoscale. here, we present and demonstrate an effective structure of non-linear metallic helical nanocone to control the intensity and polarization of plasmonic nanofocusing with different non-linear factors. the intensity distributions and polarization of the electric fields generated by the non-linear metallic helical nanocone are simulated with 3-d finite difference time-domain method, which prove that higher electric field intensity with the focusing point of about 100 nm2 and larger longitudinal component of 54.4 % can be obtained by increasing non-linear factor. the non-linear metallic helical nanocone promises potential applications in nanomanipulation nanosensing and nanolithography.