Pump-Wavelength Selective All-Optical Terahertz Metasurface with Independent Amplitude and Frequency Modulations
Jing Yuan, Zhengang Lu, Guichuan Xu, Heyan Wang, Lin Han, Jiubin Tan
Abstract
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.