Broadband large-modulation-depth low-current-triggered terahertz intensity modulator based on VO2embedded hybrid metamaterials

We experimentally demonstrate a broadband terahertz (THz) intensity modulator operating at low current and frequency range. The modulator consists of VO2and meander-wire hybrid metamaterials. The measured 3-dB bandwidth for normal incidence is 0.5 THz, while the maximum modulation depth of 99% is achieved at 0.28 A. The physical mechanism of the device's electrical tunability is attributed to an ohmic-heating-induced transition. An equivalent circuit model is proposed for the upper cut-off frequency. This scheme paves the way for a full electric control of the intensity of a THz wave at a broad band, low current, and low frequency range.