Hybrid Organic-Plasmonic Nanoantennas with Enhanced Third-Harmonic Generation

Abstract

Resonantly excited plasmonic gold nanoantennas are strong sources of third-harmonic (TH) radiation. It has been shown that the response originates from large microscopic nonlinearity of the gold itself, which is enhanced by the near-field of the plasmonic nanoantenna. To further enhance this response, one can incorporate nonlinear media into the near-fields of the nanoantenna, as an additional TH source. To obtain a significant contribution from the added medium, its nonlinear susceptibility should be comparable to that of the antenna material. Many organic materials offer the necessary nonlinear susceptibility and their incorporation is possible with simple spin-coating. Furthermore, organic materials are often susceptible to photodegradation. This degradation can be used to investigate the influence of organic materials on the hybrid system. Our investigated hybrid organic plasmonic nanoantenna system consists of a gold nanorod array and poly(methyl methacrylate) as the nonlinear dielectric medium. The experiments clearly reveal two contributions to the generated TH radiation, one from the nanoantenna itself and one from the polymer. The nonlinear response of the hybrid material exceeds the response of both individual constituents and opens the path to more efficient nanoscale nonlinear light generation.

Refractory Plasmonics without Refractory Materials

“…Our protection layer is not supposed to prohibit chemical reactions, but rather to prevent the deformation of gold. We described in a previous publication that gold in a polymer matrix is more stable upon laser exposure. The general idea of this concept has been widely used for many years. − While these publications report first strong indications of the benefits of cover layers, no systematic study of the temperature nor of the thickness dependence have been performed.…”

“…Our protection layer is not supposed to prohibit chemical reactions, but rather to prevent the deformation of gold. We described in a previous publication 32 stable upon laser exposure. The general idea of this concept has been widely used for many years.…”

Ultranarrow Second-Harmonic Resonances in Hybrid Plasmon-Fiber Cavities

“…Several approaches have been pursued in order to promote the conversion efficiency. One prominent way is to combine other highly nonlinear materials such as semiconductors, , polymers, , dielectrics, and so forth, in which the plasmonic structures are usually resonant at the excitation wavelength. Another method is using multiresonance designs.…”

Nonlinear spectroscopy of plasmonic nanoparticles

“…Ideally, one would switch χ (3) of a material while keeping χ (1) constant. A recent experiment tried to approach this scenario by photobleaching a polymer [89].…”