On-chip electrically tunable silicon whispering gallery mode resonator for THz integrated circuits

This study demonstrates an on-chip electrically tunable whispering gallery mode resonator (WGMR) operating in the terahertz (THz) band, fabricated on a silicon platform. The device consists of a micro-ring resonator with integrated platinum electrodes for voltage application. By leveraging the thermo-optic effect of silicon, the resonant frequency of the WGMR is dynamically shifted via Joule heating induced by an applied voltage, enabling continuous electrical tuning of the resonance. Experimental results show a continuous frequency tunability of 0.40 GHz/W, with the resonator exhibiting a measured quality factor (Q-factor) of 199 around 390 GHz. This work provides a compact, integrable, and efficient solution for active resonance control in THz integrated circuits, with promising applications in reconfigurable filters, modulators, sensors, and next-generation wireless communication systems.