Pump-Wavelength Selective All-Optical Terahertz Metasurface with Independent Amplitude and Frequency Modulations

• Published in: Nano letters 2024-12, Vol.24 (48), p.15414-15420
• Main Authors: Yuan, Jing, Lu, Zhengang, Xu, Guichuan, Wang, Heyan, Han, Lin, Tan, Jiubin
• Format: Article
• Language: English
• ISSN: 1530-6984; 1530-6992; 1530-6992
• DOI: 10.1021/acs.nanolett.4c04741

Tunable terahertz (THz) metasurfaces based on optical control are crucial in high-speed communication, nondestructive testing, and imaging. However, realizing independent optical tunability of multiple functions in the THz band remains challenging due to limitations in control materials. Here, we experimentally demonstrate a novel THz metasurface that employs two control materials combined with an electric-field-coupled inductor capacitor microstructure to achieve all-optical independent modulations of amplitude and frequency. Amplitude modulation is achieved through near-infrared optical pumping, reaching a maximum modulation depth of 94.42%. Broadband frequency modulation, spanning 0.21 THz, is accomplished using visible light pumping. The independent modulation function is owing to the odd-order nonlinear polarization characteristics of perovskite and the selective photon transition between the bottom Si island and the perovskite film. This work introduces a novel approach for all-optical independent modulation of THz devices, offering valuable insights for developing all-optical metasurfaces, intelligent light windows, and multidimensional ultrafast switches.