Dielectric metasurfaces with strong nonlinearities hold promise for integrated nanophotonics and quantum technologies, yet their fabrication is hindered by material-dependent challenges and limited material choices with second-order optical nonlinearities. Here, the authors employ top-down lithography and anisotropic wet etching to fabricate atomically precise, ultrathin metasurfaces highly efficient for second-harmonic generation.
- George Zograf
- Betül Küçüköz
- Timur O. Shegai