Second Harmonic Generation in Plasmonic Nanoresonators

Marco Centini,Alessio Benedetti

doi:10.1117/1.jnp.7.078501

Abstract

Nonlinear effects can be enhanced and tailored on a subwavelength scale by taking advantage of high field confinement by selective coupling among resonant plasmonic nanostructures, called plasmonic nanoresonators and nanoantennas. In particular, we focus our attention on the process of second-harmonic (SH) generation. Excitation of localized surface plasmon polaritons at the fundamental frequency in these structures can remarkably modify the response of the system by enhancing surface and/or bulk nonlinear contributions to the overall SH field. Moreover, the radiation pattern of the generated field can be controlled and directed. Indeed, the overall structure behaves as a nonlinear nanoantenna for the SH harmonic field, whose emission pattern can be tailored.

Highlights

Nonlinear effects can be enhanced and tailored on a subwavelength scale by taking advantage of high field confinement by selective coupling among resonant plasmonic nanostructures, called plasmonic nanoresonators and nanoantennas
Considering the process of second harmonic generation (SHG), the emission comes from the hot spots with an enhancement of eight orders of magnitude with respect to the portions of the structure where the field is not localized
The SHG as a function of the wire’s cross-section size was investigated in both the near- and far- field regimes, revealing that different geometries and input field polarizations lead to different emission patterns of the second harmonic field

Summary

Introduction

Nonlinear effects can be enhanced and tailored on a subwavelength scale by taking advantage of high field confinement by selective coupling among resonant plasmonic nanostructures, called plasmonic nanoresonators and nanoantennas. Excitation of localized surface plasmon polaritons at the fundamental frequency in these structures can remarkably modify the response of the system by enhancing surface and/or bulk nonlinear contributions to the overall SH field.

Results

Conclusion