Vacuum UV Nonlinear Meta-Devices

Vacuum ultraviolet (VUV) light lies in the wavelength range from 100 nm to 200nm. It is of great importance to practical applications ranging from biomedical spectroscopy to material science. Due to the strong absorption of matter in this range, producing efficient and compact VUV devices is challenging. However, it is highly desired to realize miniaturized photonic devices to further advance and explore the applications of VUV light. In this talk, we will report nonlinear metasurfaces (1-3) capable of generating and controlling VUV light. By carefully choosing the nonlinear material, rotational symmetry, and resonance mode for their unit cells, the reported metasurfaces are able to efficiently convert the incident visible laser into VUV light and control the wave properties. Metasurfaces for VUV light focusing and beam steering were fabricated and experimentally characterized. Experimental results confirm the functionalities of metasurfaces. This work points out a promising route toward novel nanophotonic devices for this valuable wavelength range.<br/><br/>References:<br/>1. M. L. Tseng et al., Vacuum ultraviolet nonlinear metalens. Sci Adv 8, eabn5644 (2022).<br/>2. M. Semmlinger et al., Generating Third Harmonic Vacuum Ultraviolet Light with a TiO2 Metasurface. Nano Lett. 19, 8972-8978 (2019).<br/>3. M. Semmlinger et al., Vacuum Ultraviolet Light-Generating Metasurface. Nano Lett. 18, 5738 (2018).