Ultraviolet Mie Resonances From LiNbO3 Nanocubes For Enhancing Nonlinear Signals

The nano-structuring of matter opened the way for advanced applications from biology to photonics. Nanostructures of materials with high refractive index and nonlinear properties have already been demonstrated in the visible-to-near-infrared range. Here we propose a new material for photonic applications in the near-ultraviolet (UV) range. We show that lithium niobate nanocubes (LiNbO3) fabricated by solvothermal synthesis are efficient scatterers in the near-UV. Furthermore, we measure the second-harmonic generation (SHG) from single LiNbO3 cubes and we demonstrate a significant SHG emission efficiency of 10-9 in the near-UV range. The LiNbO3 nanocubes can be employed as building blocks for applications in the UV range due to their low absorption, high refractive index and efficient SHG emission. They can be successfully used as bio-imaging markers. The LiNbO3 nanocubes also interact strongly with light and modify the amplitude and phase of wave-fronts in the near-UV range, a first step for obtaining UV metasurfaces.