Active terahertz wave modulator based on molybdenum disulfide

Abstract A high-efficiency active terahertz wave modulator based on a molybdenum disulfide (MoS 2 )/germanium (Ge) structure was investigated. Spectrally broadband modulation of the THz transmission was obtained using optical control over the frequency range from 0.2 to 2.6 THz. The MoS 2 monolayer structure on germanium demonstrated enhancement of the terahertz modulation depth when compared with those of bare Ge and the graphene/Ge structures. The results show that the MoS 2 -based modulator demonstrated even higher modulation efficiency than the graphene-based device. The modulation enhancement mechanism that originated from increased conductivity was analyzed. The optical modulation properties of the MoS 2 /Ge device show tremendous promise for applications in terahertz modulation and switching.