Optimization of plasmonic high harmonic generation in a 3D pyramidal nanowaveguide by tuning the aspect ratio of its rectangular cross section and chirp and polarization of femtosecond incident pulses

摘要

Surface plasmon polariton propagation in a pyramidal 3D nanostructural waveguide with a rectangular cross section carved in silver is studied using the finite-difference time-domain method. The effect of the amount of aspect ratio of rectangular sides on the enhancement factor is studied and for r = 0.4 a maximum field enhancement of 96 dB is obtained. Furthermore, it is observed that by adjusting the amount of the incident chirp, this factor can increase up to 100 dB. It is also found that polarization of the incident beam does not change the optimum value of the aspect ratio, but the maximum enhancement factor for a linearly polarized and elliptically polarized beam along y axis is larger. (C) 2015 Optical Society of America