Ultrafast Frequency Shift of Electromagnetically Induced Transparency in Terahertz Metaphotonic Devices

Recently, the actively controlled meta-atoms have been employed to manipulate terahertz (THz) waves allowing for the implementation of many functionalities operating. A salient example of such systems is the electromagnetically induced transparency (EIT) metaphotonic device, which opens up a new avenue for THz manipulations. However, these devices are currently limited to be tuned at a given frequency, which severely impedes their practical applications. Here, novel photo-active THz meta-atoms are proposed, whose EIT resonance is equipped with a frequency tuning functionality up to 36%. At different levels of optical pumping power, a substantial modulation of EIT resonance is realized at the fundamental and shifted frequency, respectively. Moreover, the ultrafast dynamics manifest the switching time scale of approximate to 1 ns. This configuration is easily extensible by other types of stimuli, which may contribute to the development of multifunctional active tuning meta-photonic systems.