High-Efficiency Second Harmonic Generation from a Single Hybrid ZnO Nanowire/Au Plasmonic Nano-Oligomer

Abstract

We introduce a plasmonic-semiconductor hybrid nanosystem, consisting of a ZnO nanowire coupled to a gold pentamer oligomer by crossing the hot-spot. It is demonstrated that the hybrid system exhibits a second harmonic (SH) conversion efficiency of ∼3 × 10(-5)%, which is among the highest values for a nanoscale object at optical frequencies reported so far. The SH intensity was found to be ∼1700 times larger than that from the same nanowire excited outside the hot-spot. Placing high nonlinear susceptibility materials precisely in plasmonic confined-field regions to enhance SH generation opens new perspectives for highly efficient light frequency up-conversion on the nanoscale.

High-efficiency broadband second harmonic generation in single hexagonal GaAs nanowire

“…As previously reported in the literature, NWs composed of several different materials, including alkaline niobates 21 , ZnO 22–24 , ZnTe 20 , ZnSe 25 , ZnS 16 , CdS 13, 26 , GaAs 17, 19, 27 , GaN 18 , GaP 28, 29 , InP 30 , perovskite Na 0.5 Bi 0.5 TiO 3 31 , graphene 32 and Pt 33 , can be excited to generate second harmonic light. Among these materials, GaAs NWs are excellent candidate materials for SHG because of the high second-order nonlinear optical susceptibility of GaAs.…”

“…demonstrated that a vertical free-standing GaAs-NW array could generate broadband SHG signals when excited using femtosecond (fs) lasers and briefly mentioned that an isolated single NW is also capable of producing broadband SHG signals 34 . However, the conversion efficiency of the broadband SHG signals that were generated, which is very important for SHG in practice 24, 26 was not given. In this work, we systematically investigated SHG using a single hexagonal GaAs NW.…”

Low‐Power Continuous‐Wave Second Harmonic Generation in Semiconductor Nanowires

“…Until now, the reported SHG experiments of NWs were realized using pulsed lasers with high peak powers (≈100 W), which limits their device applications, especially for nanoscale coherent light sources and integrated photonic circuits. To improve SHG efficiencies in NWs, hybrid nanostructures consisting of NWs and metal materials were widely exploited to provide localized surface plasmons for light field enhancement . Unfortunately, the large ohmic loss and low coupling efficiency of the plasmonic nanostructures still make it inevitable to pump SHGs with pulsed lasers.…”

Significantly Enhanced Third Harmonic Generation Using Individual Au Nanorods Coated With Gain Materials

“…The locally enhanced electromagnetic field near the plasmonic nanostructures can be used in various applications ranging from solar cells [1] to bio-probe based imaging [2], surface enhanced Raman scattering (SERS) [3], and cancer therapy [4]. In addition to the enhanced the local electronic field, researchers are currently devoting more attention to optical frequency upconversion based on LSPR, e.g., second harmonic generation [5]- [14], third harmonic generation (THG) [15]- [20], and four-wave mixing [21]- [23]. These optical upconversion effects by using LSPR can be widely applied in various fields.…”

“…These systems are constructed by bringing two or more NPs in close proximity in order to enhance, by several orders of magnitude, the electric field in the hot spot [12], [13], [16], [17]. The generation intensity of the higher order harmonics has also been improved by introducing specific nanostructures with large high-order nonlinear susceptibility into the corresponding gap system [14], [18], [19]. Although highly enhanced upconverting generations have been obtained from these systems, their characteristics are highly dependent on the precision control of the shape and position of each nanostructure in the gap system [27].…”