Innovative active terahertz modulator based on dynamic graphene-silicon arrays

This paper presents an innovative active terahertz (THz) modulator that utilizes dynamic graphene-silicon arrays (DGSAs) to overcome the challenges of dynamically manipulating THz waves. The DGSA combines the exceptional electrical properties of graphene with the enhanced optical absorption capabilities of silicon arrays, enabling dual-mode active control through optical pumping and electrical biasing. An 808 nm laser is used to photoexcite carriers in the silicon arrays for optical pumping while a bias voltage modulates the Fermi level of graphene, subsequently varying Si conductivity and influencing the transmission properties of THz waves. Simulations have demonstrated modulation depths of up to 94% at 2.5 THz in the transmission mode and 89% at 1 THz in the reflection mode. Furthermore, this study delves into a theoretical analysis and numerical simulations, exploring the modulation mechanisms, including the role of graphene's Drude model and PN junction effects. These insights provide a robust theoretical framework for understanding the DGSA's operation and lay a solid foundation for the design and optimization of high-performance THz modulation devices. (c) 2024 Optica Publishing Group. All rights, including for text and data mining (TDM), Artificial Intelligence (AI) training, and similar technologies, are reserved.