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.