▎ 摘 要
We propose a triple-band, tunable, and highly efficient reflected cross-polarization converter in the mid-infrared. The converter is composed of a metal ground plane, a dielectric layer, and double L-shaped graphene patch arrays. Triple bands (36.15, 48.95, and 52.20 THz) of cross-polarization conversion are achieved due to the superimposition of the two reflected components with a near 180 degrees phase difference. The tunable performance of our proposed converter can be realized by changing the Fermi energy and electron scattering time. Our idea is verified by finite element method simulation and paves a way to the design of multi-band polarization converters. (C) 2018 Optical Society of America