Reconfigurable linear polarization conversion based on spatial-order kirigami metasurfaces

Abstract

With the development of intelligent technology, it is essential to develop polarization-conversion devices with adaptable electromagnetic (EM) performance for practical applications. Up to now, most of attempts have relied on PIN diodes and varactor diodes for electrical tuning, typically featuring simplicity and timelineness. However, the shortcomings are also notable, such as less degrees of freedom (DoFs), more complex circuits and more expensive. In view of this, here we propose a kind of spatial-order metasurface for reconfigurable polarization conversion based on kirigami concept. By adjusting the folding angle <i>β</i>, the interaction between neighboring dipoles can be progressively changed and thus the operation frequency of polarization conversion can be shifted. Such a mechanical reconfigurable strategy brings about more DoFs for tuning and is cheaper and extraordinary convenient in practice. To verify the feasibility of our concept, a proof-of-concept spatial-order kirigami metasurface is proposed for the dual-band reconfigurable linear polarization conversion based on asymmetric chiral split ring resonators (SRRs). Experimental results show that the linear polarization operates at 5 and 5.8 GHz when folding angle is <i>β</i> = 10°, these frequencies are shifted to 5.8 and 7.2 GHz when <i>β</i> = 45°: a tuning range is expanded by 18.5%. In addition, the Poisson’s ratio and relative density of proposed kirigami metasurface as a function of <i>β</i> are also theoretically analyzed. The results show that the Poisson’s ratio increases with the value of <i>β</i> increasing. The relative density can be reduced to 1.5% of its unfolded planar counterpart. Our spatial-order kirigami metasurface strategy paves the way for implementing the reconfigurable linear polarization conversion and multifunctional devices.