Full-space terahertz metasurface based on thermally tunable InSb

Abstract

Terahertz (THz) metasurfaces have potential research value in high-quality molecular imaging, high-speed broadband communication, biology, etc. In this paper, thermally tunable full space metasurface was proposed and analyzed by using Finite Difference Time Domain method based on Pancharatnam–Berry phase modulation and InSb temperature characteristic. At 220 K, a metasurface composed of InSb elements can simultaneously achieve efficient transmission and reflection of the incident circularly polarized light at 0.8 THz and 1.15 THz, respectively. On the contrary, at 360 K, the metasurface absorbs all of the incident terahertz waves, essentially turning off the incident beam. In addition, dynamically tunable metalenses were proposed and used to generate focused vortex light. The proposed metasurface provides a potential direction for developing an efficiency-tunable PB terahertz device in the future.

Reprogrammable reflection-transmission integrated coding metasurface for real-time terahertz wavefront manipulations in full-space

“… Refs. Frequency Real-time tunable reflection and transmission Real-time tunable phase Active element Same frequency Same polarization 40 GHz No No – No No 41 GHz Yes No PIN diode Yes Yes 42 , 43 GHz Yes Yes PIN diode Yes Yes 52 , 53 , 56 THz No No - No No 44 , 51 , 54 , 60 THz Yes No Vo2 Yes Yes This work THz Yes Yes Graphene Yes Yes …”

“…However, achieving control of reflected and transmitted waves in MSs is not limited to the microwave band, and efforts have also been made in the THz band. In 51 , Dong et al the proposed structure achieves control of the reflection and transmission of EM waves in two different frequency bands through the use of InSb temperature changes. Additionally, phase control is obtained by adjusting the dimensions of the structure.…”