Design of a graphene-based plasmonic-induced transparency structure for optical switching, sensing, and slow-light applications

This paper presents a graphene-based plasmonic-induced transparency (PIT) structure. The design exhibits reconfigurable multifunctionality, simultaneously enabling high-performance optical switches, refractive index sensing, and slow-light applications. For optical switch applications, the structure achieves a modulation depth of 99.15%, an insertion loss of 0.02 dB, and an extinction ratio of 20.70 dB. In refractive index sensing, it exhibits remarkable sensitivity (1.44 THz/RIU) with ideal linearity (R² is close to 1). In terms of slow-light properties, the group index reaches 2694. This work provides critical design principles for developing multifunctional photonic devices, including filters, optical switches, sensors, and slow-light components.