Active optical modulator based on a metasurface in the terahertz region

Dual-band passband terahertz filter based on multilayer metamaterial

We have theoretically verified the design of dual-band passband terahertz filter using multilayer metamaterial. The top and bottom layers are composed of periodically branching structure metallic patterns, which are exactly the same. The middle layer consists of a periodically metallic square aperture. The three metallic layers are separated by two thin dielectric layers. An equivalent circuit model is used to simplify the design procedure of the proposed structure. The performance of the terahertz filter is analyzed via equivalent circuit model together with the full wave CST method. The results show that the proposed structure provides two passbands. One is the center frequency of 0.32 THz with -3dB bandwidth of 164 GHz, and the other is the center frequency of 0.74 THz with -3dB bandwidth of 176 GHz.

Performance comparison of the electromagnetic induction transparency effects for two U-shaped resonators having different opening directions

This paper gives the design of electromagnetically induced transparency effect using two U-shaped resonators with different opening directions (same direction and opposite direction). It is revealed that extremely similar transparency effect can be found for the two cases. The reason is that the two structures have the same sizes. However, the change in position of the two U-shaped resonators in the opposite opening has a significant effect on the transparent peak which is mainly reflected in the broadening of the broadband and the frequency shift of the working frequency, while there is almost no change in resonance performance for the same opening. We provide the field distributions for analyzing the causes of these different results. We believe these performance can guide future research.