3D-printed silica with nanoscale resolution.

Fabricating inorganic materials with designed three-dimensional nanostructures is an exciting yet challenging area of research and industrial application. Here, we develop an approach to 3D print high-quality nanostructures of silica with sub-200 nm resolution and with the flexible capability of rare-earth element doping. The printed SiO ₂ can be either amorphous glass or polycrystalline cristobalite controlled by the sintering process. The 3D-printed nanostructures demonstrate attractive optical properties. For instance, the fabricated micro-toroid optical resonators can reach quality factors (Q) of over 10 ⁴ . Moreover, and importantly for optical applications, doping and codoping of rare-earth salts such as Er ³⁺ , Tm ³⁺ , Yb ³⁺ , Eu ³⁺ and Nd ³⁺ can be directly implemented in the printed SiO ₂ structures, showing strong photoluminescence at the desired wavelengths. This technique shows the potential for building integrated microphotonics with silica via 3D printing.
(© 2021. The Author(s), under exclusive licence to Springer Nature Limited.)