Electrically triggered dual-band tunable terahertz metamaterial band-pass filter based on Si₃N₄–VO₂–Si₃N₄ sandwich*

Abstract

Abstract We experimentally demonstrate an electrically triggered terahertz (THz) dual-band tunable band-pass filter based on Si 3 N 4 –VO 2 –Si 3 N 4 sandwich-structured hybrid metamaterials. The insulator–metal phase transition of VO 2 film is induced by the Joule thermal effect of the top metal layer. The finite-integration-time-domain (FITD) method and finite element method (FEM) are used for numerical simulations. The sample is fabricated using a surface micromachining process, and characterized by a THz time-domain-spectrometer (TDS). When the bias current is 0.225 A, the intensity modulation depths at two central frequencies of 0.56 THz and 0.91 THz are about 81.7% and 81.3%, respectively. This novel design can achieve dynamically electric–thermo–optic modulation in the THz region, and has potential applications in the fields of THz communications, imaging, sensing, and astronomy exploration.