Coexistence of circular dichroism and asymmetric transmission in a stretchable chiral metamaterial

A stretchable chiral metamaterial with Au nanoslits and L-shaped and T-shaped Au patterns (SCMM-NLT), which can simultaneously produce circular dichroism (CD) and asymmetric transmission (AT) effects for circularly polarized waves in the mid-infrared region, is proposed. The peak values of CD and AT effects reach 20.4% and −20.4% at the resonance wavelength of 23.4 µm, respectively, which originate from the excitation of the bonding and antibonding modes. We use the transmission matrix to analyze the simultaneous appearance of CD and AT effects. By stretching SCMM-NLT, the bands of CD and AT occur at the redshift phenomenon, which is attributed to the decrease of Coulomb force between the positive and negative charge accumulated at both ends of the structure. All results are calculated by the FEM-based software COMSOL Multiphysics. In the future, our findings could be applied to wearable electronic devices, such as refractive index sensors.