Abstract-Dual-wavelength Terahertz Metalens Based on Geometric Phase Metasurface

Tailei Wang, Hang Li, Rensheng Xie, Sensong An, Shouzheng Zhu, Guohua Zhai, Wei Guo, Hualiang Zhang, and Jun Ding

https://www.osapublishing.org/abstract.cfm?uri=CLEO_AT-2019-JTh2A.14

We proposed a novel dual-wavelength meta-atom, which could be used to independently modulate the geometric phase of the circularly polarized incident wave at two terahertz frequencies. A prototype dual-wavelength metalens has been designed and verified at the terahertz regime.

© 2019 The Author(s)

Abstract-Dual-Wavelength Terahertz Metasurfaces with Independent Phase and Amplitude Control at Each Wavelength

• Jun Ding
• , Ningning Xu
• , Han Ren
• , Yuankun Lin
• , Weili Zhang
•  & Hualiang Zhang

http://www.nature.com/articles/srep34020

We have designed, fabricated and characterized dual-wavelength metasurfaces that function at two assigned terahertz wavelengths with independent phase and amplitude control at each wavelength. Specifically, we have designed a dual-wavelength achromatic metasurface-based deflector deflecting the incident wave to the same direction at two selected wavelengths, which has circumvented the critical limitation of strong wavelength dependence in the planar metasurface-based devices caused by the resonant nature of the plasmonic structures. As a proof of concept demonstration, the designed dual-wavelength achromatic deflector has been fabricated, and characterized experimentally. The numerical simulations, theoretical predictions, and experimental results agree very well with each other, demonstrating the property of independently manipulating the phase profiles at two wavelengths. Furthermore, another unique feature of the designed metasurface is that it can independently tailor both the phase and amplitude profiles at two wavelengths. This property has been numerically validated by engineering a metasurface-based device to simultaneously generate two diffraction orders at two desired wavelengths.