High performance metamaterials-high electron mobility transistors integrated terahertz modulator

We demonstrate an electric control metamaterials-high electron mobility transistors (HEMTs) integrated terahertz (THz) modulator whose switching ability is developed by utilizing the symmetric quadruple-split-ring resonators (SRRs) metamaterial configuration and operating voltage is reduced by incorporating the HEMT elements. Meanwhile, the high switching speed of the HEMT implies that the THz modulator has a high potential in modulation speed. Under a reverse gate voltage of −4 V, the THz modulator exhibits a modulation depth of 80% at 0.86 THz and a phase shift of 0.67 rad (38.4°) at 0.77 THz, respectively. In addition, a modulation speed over 2.7 MHz is achieved and an improvement in the modulation speed of hundreds of MHz with optimum RC time constant is expected to achieve for the THz modulator.