Active terahertz modulator with dynamic graphene-silicon nanoarrays

This paper introduces an innovative active terahertz (THz) modulator that employs dynamic graphene-silicon nanoarrays (DGSN) to address the challenges of dynamically manipulating THz waves. The DGSN combines the exceptional electrical properties of graphene with the enhanced optical absorption capabilities of silicon nanoarrays, thereby enabling dual-mode active control via optical pumping and electrical biasing. An 808 nm laser is used to photoexcitation carriers in the silicon nanoarrays for optical pumping, while a bias voltage modulates the Fermi level of graphene, subsequently altering its conductivity and influencing the transmission properties of THz waves. Simulations reveal modulation depths of up to 59% and 99% under optical pumping and dual-mode control, respectively. This study provides theoretical insights into the modulation mechanisms and lays a solid foundation for the design and optimization of high-performance THz modulation devices, showcasing the immense potential of the DGSN in advancing THz technology.