Terahertz non-reciprocal transmission in silicon photonic crystal metasurfaces with high-Q quasi-bound states.

Non-reciprocal devices can be used to protect terahertz radiation sources and detectors from system echo reflection and noise interference. We propose an asymmetric groove silicon photonic crystal cylindrical metasurface, which generates high- quasi-bound states (q-BIC) and enhances nonlinearity. At terahertz wave incident intensity of 0.

Terahertz nonreciprocal characteristics based on a grating metasurface.

Terahertz nonreciprocal devices have achieved manipulation of terahertz waves through active control mechanisms, becoming an indispensable building block in terahertz systems. In this paper, we propose a grating metasurface that achieves high nonreciprocity of the reflection mode in the terahertz range. The metasurface structure is composed of vanadium dioxide and amorphous chalcogenide glass with grooves.

Tunable multifunctional terahertz metasurface based on an indium antimonide medium.

Active adjustable terahertz multifunctional devices are crucial for the application of terahertz technology. In this paper, we propose a composite metasurface structure based on an indium antimonide metal octagonal pattern, which achieves different functional switching by controlling the phase state of indium antimonide material under different ambient temperatures. When indium antimonide exhibits in the dielectric state, by stacking and encoding the unit cell, the designed metasurface has the functions of two-beam splitting beam superposition, vortex beam and quarter beam superposition, and dual vortex beam superposition for circularly polarized and linearly polarized wave incidence.

Flexible manipulation terahertz beam based on an all-dielectric metasurface by utilizing addition and convolution algorithms.

The flexibly manipulated terahertz wave is currently a hot research topic. To address this challenge, we proposed an all-dielectric coding metasurface for shaping the terahertz wave including beam splitting, beam deflection, vortex beam generators, and a vortex beam and multi-beam splitting combination by combining addition with the convolution theorem. This work represents what we believe to be a new method of combining terahertz wave regulation with digital signal processing and opens up the versatile design ideas of multifunctional metadevices.

Reconfigurable three multi-mode terahertz metasurface.

We designed a three reconfigurable multi-mode terahertz metasurface based on a concentric elliptical ring structure. The proposed unit cell is a concentric elliptical ring composed of copper, vanadium oxide and photosensitive silicon from the inside ring to the outside ring. The conductivity of photosensitive silicon and vanadium oxide can be adjusted by changing the external operating temperature and pump light intensity.