Fabrication of Ge2Sb2Te5 metasurfaces by direct laser writing technique

•Tunable high-contrast GST metasurfaces.•Fast fabrication of high-resolution GST metasurfaces on sapphire substrates.•Direct femtosecond-laser scribing on GST films.•Sapphire vs. glass substrate for DLW scribing methods. We experimentally demonstrate fabrication of the tunable high-contrast periodic metasurfaces from 150 nm thick Ge2Sb2Te5 films sputtered onto glass and sapphire substrates by exploiting direct laser writing technique. We find that the use of sapphire substrate provides better accuracy of metasurface segments due to higher thermal conductivity. The advantages of the demonstrated method are its simplicity, rapidity, robustness, and the ability of tailoring dielectric properties of the fabricated structures. This is of crucial importance for the engineering of robust and tunable metasurfaces for applications in the field of telecommunications and information processing.