ABSTRACT
In this paper, a new tuning strategy is proposed by incorporating a pneumatically actuated metamaterial to achieve on-demand polarization manipulation at THz frequencies. Through controlling the actuation pressure, the device function can be flexibly switched among three types of polarization conversion capabilities within the same operation frequency band, from 1.3 THz to 1.5 THz, in which the mutual conversion between linear polarization and circular polarization, such as a quarter-wave plate, and handedness inversion between circular polarizations as a helicity inverter as well as a helicity keeper, have been successfully achieved between the incidence and reflection. Moreover, the intrinsic tuning mechanism for the polarization manipulation is also discussed.
ABSTRACT
Aiming to achieve real 3D chiral metamaterial structure, a new strategy is proposed. During which a 2D to 3D conversion mechanism based on integrated pneumatic actuator is used to provide a relatively simple yet effective process solution. With this concept, only the lithography-based planar process is required, and a symmetric tuning capability over the shape of the 3D chiral metamaterial as well as its chirality both can be achieved through controlling the applied pressure. At the same time, the resultant optical activity and circular dichroism associated with this tunable 3D chiral metamaterial are also studied and exciting characteristics demonstrating enantiomeric symmetry have been successfully obtained as well.
