Dynamical chiral metamaterial with giant optical activity and constant Chirality over a certain frequency band

Abstract

We demonstrate numerically and experimentally a dynamical chiral metamaterial that uniaxially creates giant optical activity and circular dichroism. In addition, the structure gives a high negative refractive index due to the large chirality. The proposed chiral metamaterial includes four L attached cross (FLAC) wire strips and offers a simple geometry, flexibility and more efficient results for chiral metamaterial applications such as polarization rotator, EM filter and so on. The experimental results are in a good agreement with the numerical simulation. It can be seen that FLAC wire strips based chiral metamaterial can also be used to achieve natural-small chirality with a constant value in a wide frequency range between 3.5-4.5 GHz. This is also another crucial feature of the structure. Therefore, the proposed chiral metamaterial with constant chirality value can be used to design novel EM devices such as polarization converter, anti-reflection filters for a certain frequency range.