Hexagonal boron nitride second harmonic generation using gold nanorods with continuous laser source

Abstract

Here we demonstrate second harmonic generation in two-dimensional hexagonal boron nitride (hBN) using plasmonic nanorods with 10 mW continuous source pump at 973 nm. Gold nanorods with resonance at 980 nm are used to enhance the electric field intensity near hBN nanoflakes, which showed $6.5 \times 10^{5}$ times enhancement in finite-difference time-domain simulations. A drop-coated mixture of hBN nanoflakes and gold nanorods showed a second harmonic signal at 486.5 nm while no second harmonic generation was seen for hBN nanoflakes or gold nanorods alone. This scheme can pave the road for ultra-fast imaging and cost-effective detection at telecommunication wavelength using silicon-based detectors.