Ultrafast Frequency Shift of Electromagnetically Induced Transparency in Terahertz Metaphotonic Devices

摘要

Recently, the actively controlled meta-atoms have been employed tomanipulate terahertz (THz) waves allowing for the implementation of manyfunctionalities operating. A salient example of such systems is theelectromagnetically induced transparency (EIT) metaphotonic device, whichopens up a new avenue for THz manipulations. However, these devices arecurrently limited to be tuned at a given frequency, which severely impedestheir practical applications. Here, novel photo-active THz meta-atoms areproposed, whose EIT resonance is equipped with a frequency tuningfunctionality up to 36%. At different levels of optical pumping power, asubstantial modulation of EIT resonance is realized at the fundamental andshifted frequency, respectively. Moreover, the ultrafast dynamics manifest theswitching time scale of ≈1 ns. This configuration is easily extensible by othertypes of stimuli, which may contribute to the development of multifunctionalactive tuning meta-photonic systems.