A lattice-enhanced light-driven terahertz meta-device with decoupled resonant modulation†

Light-driven terahertz metasurface-based platforms, characterized by flexible and dynamic characteristics, exhibit significant potential in advancing optics applications. Tremendous effort has been devoted to exploring an effective way to boost the performance of optical elements. However, the typical mechanisms to design superior devices, including the nonlinear plasmonic, local-field construction, and Kerr effect are limited to the narrow working band and single function accompanied by efficiency loss, high-standard machining accuracy, and trade-offs between operating rate and signal-to-noise ratio. Here, a direct, efficient, and universal strategy for boosting the performance of light-driven devices is proposed to overcome these limitations. The performance of tri-function ultrafast switches operating at an ultrafast rate of 2 ps, including broadband single-amplitude modulators as well as decoupled resonant modulation with annihilation and enhancement, is manipulated by adjusting the lattice period. At all operating frequencies, the group delay characteristics are suppressed for high-fidelity communication. Furthermore, the loss-sensitive performance of the proposed metasurfaces, possessing highly precise sensing functions by light-driven calibration, could improve to 5/RIU through lattice enhancement. Thus, this work provides a simple and generalized paradigm for advancing ultrafast integrated optical devices and reusable precise sensors.