Perfect absorption frequency modulation, optical switching and slow-light multifunctional integrated device based on plasmon-induced absorption

• Published in: Optics and laser technology 2024-01, Vol.168, p.109840, Article 109840
• Main Authors: Gao, Enduo, Cao, Guangtao, Deng, Yan, Li, Hongjian, Chen, Xiaoshuang, Li, Guanhai
• Format: Article
• Language: English
• Subjects: Absorption; Bound states in the continuum; Graphene; Optical switch; Slow-light
• ISSN: 0030-3992; 1879-2545
• DOI: 10.1016/j.optlastec.2023.109840

•We propose a novel PIA formed by strong coupling between the quasi-BIC and graphene surface plasmon resonance.•The dynamic modulation range of perfect absorption is up to 4.95 THz.•TM-TE optical switches with the 100 % modulation depth and 0.040 insertion loss can be implemented.•Excellent slow-light devise with 10.3 ps group delay can be realized. It is necessary to explore new mechanisms of plasmon-induced transparency (PIT) formation to achieve high-performance optical multifunction devices. Here, we introduced a symmetry-protected quasi bound states in the continuum (quasi-BIC) in the vicinity of the graphene plasmon resonance (GPR) mode to achieve a tunable plasmon-induced absorption (PIA) with 99.0 % and 99.4 %, which is the result of coupling between the bright modes. PIA supported by quasi-BIC has outstanding characteristics in both optical switching and slow light, with amplitude modulation depth up to 100 %, insertion loss below 0.04 dB, and group delay up to 10.3 ps. Significantly, it also solves the challenge that the absorption of the graphene system is reduced during dynamic modulation of electromagnetic waves. The dynamic modulation range of perfect absorption is up to 4.95 THz, which is much higher than any work that has been reported. We believe that the proposed structure provides a great reference for the future research direction of PIT and stimulates the development of high-performance multifunctional devices.