No abstract

In this paper, we propose a structure based on double-layer graphene-based planar chiral metasurface with J-shaped pattern to generate asymmetric transmission, which can reach to 16.64%.

Circular dichroism (CD) of a stretchable chiral metamaterial with bilayer L-shaped and T-shaped Au patterns on the Polydimethylsiloxane substrate (SCMM-BLT) is investigated theoretically. Due to the excitation of plasmonic hybridization modes, CD effect happens. SCMM-BLT can produce large optical chirality (OC) of 53.6% in mid-infrared region, and we attribute the double bands of CD to the excitation of the bonding and antibonding modes. By stretching SCMM-BLT, the bands of CD shift to longer wavelengths, which prove SCMM-BLT can be a candidate as the tunable chiral metamaterial. Our findings pave a way in designing wearable electronic devices, such as sensors.

In this manuscript, we propose a graphene metasurface composed of an L-shaped pattern to achieve a tunable circular dichroism under oblique incidence in the mid-infrared region. For our graphene extrinsically 3D-chiral structure, there are two graphene localized surface plasmons resonant modes at the wavelength of 11.05 and 16.69 μm. A broad bandwidth circular dichroism between the two modes is generated, so are two bands of negative circular dichroism (circular dichroism is minus). The circular dichroism can be enhanced by increasing the incident angle. Maximal circular dichroism can reach 24.64% when the incident angle is 60°. The mechanism of circular dichroism generation is attributed to the strong interaction between electric and magnetic dipoles. Besides, the circular dichroism can be tuned by changing the Fermi energy and is affected by the intrinsic relaxation time. It will have a wide application in photonic devices, which can promote the development of analytical chemistry and numerous other areas.

A stretchable chiral metamaterial with L-shaped and T-shaped Au patterns (SCMM-LT) is proposed to generate asymmetric transmission (AT) for circularly polarized waves on the polydimethylsiloxane substrate in the mid-infrared region. The peak value of AT can reach 50.02% at the resonance wavelength of 19.1 µm, owing to the enantiomerically sensitive plasmons. With stretching along the x axis and the y axis. respectively, the band of AT shifts to a longer wavelength, which proves the SCMM-LT can be a candidate as the tunable chiral metamaterial. In the future, the proposed stretchable chiral metamaterial could potentially possess high applicability for wearable electronic devices in a variety of sensor fields.