  The ancient paper craft of kirigami has recently emerged as a potential tool
for the design of functional materials. Inspired by the kirigami concept, we
propose a class of kirigami-based metamaterials whose electromagnetic
functionalities can be switched between nonchiral and chiral states by
stretching the predesigned split-ring resonator array. Single-band, dual-band
and broadband circular polarizers with reconfigurable performance are
experimentally demonstrated with maximum circular dichroisms of 0.88, 0.94 and
0.92, respectively. The underlying mechanism is explained and calculated via
detailed analysis of the excited multipoles, including the electric, magnetic,
and toroidal dipoles and quadrupole. Our approach enables tailoring the
electromagnetic functionalities in kirigami patterns and provides an alternate
avenue for reconfigurable optical metadevices with exceptional mechanical
properties.
