Ultrafast All-Optical Switching Modulation of Terahertz Polarization Conversion Metasurfaces Based on Silicon

Qiangguo Zhou; Qinxi Qiu; Tuntan Wu; Yongzhen Li; Zhiming Huang

doi:10.1021/acsomega.3c08355

Ultrafast All-Optical Switching Modulation of Terahertz Polarization Conversion Metasurfaces Based on Silicon

ACS Omega. 2023 Dec 11;8(50):48465-48479. doi: 10.1021/acsomega.3c08355. eCollection 2023 Dec 19.

Authors

Qiangguo Zhou^{1

2}, Qinxi Qiu¹, Tuntan Wu^{1

2}, Yongzhen Li^{1

2}, Zhiming Huang^{1

2

3

4

5

6}

Affiliations

¹ State Key Laboratory of Infrared Physics, Shanghai Institute of Technical Physics, Chinese Academy of Sciences, 500 Yu Tian Road, Shanghai 200083, P. R. China.
² University of Chinese Academy of Sciences, Chinese Academy of Sciences, 19 Yu Quan Road, Beijing 100049, P. R. China.
³ Hangzhou Institute for Advanced Study, University of Chinese Academy of Sciences, 1 Sub-Lane Xiangshan, Hangzhou 310024, P. R. China.
⁴ Institute of Optoelectronics, Fudan University, 2005 Songhu Road, Shanghai 200438, P. R. China.
⁵ Key Laboratory of Space Active Opto-Electronics Technology, Shanghai Institute of Technical Physics, Chinese Academy of Sciences, 500 Yu Tian Road, Shanghai 200083, P. R. China.
⁶ School of Microelectronics, Shanghai University, 20 Cheng Zhong Road, Shanghai 201800, P. R. China.

Abstract

With the development of ultrafast optics, all-optical control of terahertz wave modulation based on semiconductors has become an important technology of terahertz wave regulation. In this article, an ultrawideband terahertz linear polarization converter consisting of a double-layered metasurface is first proposed. The polarization conversion ratio of the device is ∼ 100% at 0.2-2.2 THz, and the transmission of copolarization approaches zero in the full band, which demonstrates the ability of high-purity output with rotating input linear polarization of 90° over an ultrawideband. By analysis of the surface current and electric field distribution, the physical mechanism of polarization conversion is elucidated. In addition, the influence of important geometric parameters on the device is discussed and analyzed in detail, which provides theoretical support for the design of high-performance polarization converters. More importantly, by introducing semiconductor silicon to construct an actively controllable metasurface, we design all-optical polarization converters based on a meta-atomic molecularization metasurface and all-dielectric metasurface; the dynamically tunable ultrawideband linear polarization conversion is realized under optical pumping, which solves the inherent problem of the performance of the metasurface polarization converters. Numerical simulation shows that the switching response of the two types of actively controllable devices under optical pumping is about 700 and 1800 ps, respectively, and can manipulate polarized wave conversion ultrafast, which brings new opportunities for all-optical controlled ultrafast terahertz polarization converters. Our results provide a feasible scheme for the development of state-of-the-art active and controllable ultrafast terahertz metasurface polarization converters, which have great application potential in short-range wireless terahertz communication, ultrafast optical switches, the transient spectrum, and optical polarization control devices.