Dynamically tunable metamaterial device for bidirectional optical switching in terahertz

Abstract A dynamically tunable metamaterial device (DTMD) with switchable functionality between broadband transmission and absorption is proposed, utilizing vanadium oxide (VO 2 ) and graphene. By varying the conductivity of VO 2 from 0 S m −1 to 200 000 S m −1 , the device enables dynamic switching between broadband transmission and absorption modes. This device achieves broadband absorption exceeding 90% with an absorption bandwidth of 5.64 THz, ranging from 2.42 THz to 8.06 THz. In transmission mode, broadband transmission rates above 90% are achieved across the 2.28–8.98 THz spectra. More importantly, the proposed device operates as a bidirectional optical switch, demonstrating a maximum modulation depth of 99.99%, as well as polarization-independent operation and wideband characteristics. This DTMD holds potentialities for terahertz optoelectronic applications, including optical switches, modulators, and broadband absorbers, etc.