Invited Article: Nano-kirigami metasurfaces by focused-ion-beam induced close-loop transformation

Abstract

Reducing fabrication difficulties while maintaining structural complexities and functionalities is one of the key challenges faced by the applications of nanophotonic devices. Here we demonstrate an exotic metasurface by using a simple close-loop nano-kirigami method. Based on the focused-ion-beam induced continuous shape transformation of a suspended ultra-thin gold film, pinwheel-like metasurfaces with uniaxial broadband polarization conversion and handedness-sensitive phase properties are readily fabricated. By deliberately patterning the metasurfaces periodically with opposite handedness, high-contrast cross-polarized diffractions are successfully observed in both linear and radial configurations. The demonstrated new types of metasurfaces, together with their suspended features for reconfiguration potentials, can open up new possibilities for the exploration of functional and reconfigurable micro-/nano-photonic and electronic devices.