Muti-band terahertz modulator based on double metamaterial/perovskite hybrid structure

We proposed a novel multi-frequency-band terahertz modulator working for free-space terahertz radiation. The unit cell of the metamaterial/perovskite hybrid structure, which consists of split-ring resonator, is patterned on silica with a dielectric constant of epsilon = 3.75, a loss tangent of tan delta = 0.01 and concentric double rings are fabricated on the bottom of the silica with the thickness of 200 nm. The split gaps of split-ring resonators are filled with perovskite quantum dots thin film. The terahertz wave modulation mechanism of our structure is numerically investigated by using CST Microwave Studio. We have also employed an equivalent circuit model (ECM) to validate our numerically simulated observations. The results exhibit four different frequency carrier wave signal modulation at 0.42THz, 0.83THz, 1.18THz and 1.62THz with modulation depth (> 99%) and megahertz modulation speed. This work demonstrates a new approach for realizing multi-band terahertz amplitude shift keying (ASK) modulator for terahertz wavelength division multiplex (WDM) communication.