Hybrid Graphene-WS2 Mach-Zehnder modulator on passive silicon waveguide

2D materials such as graphene have attracted a lot of interest in recent years because of their unique electrical and optical properties [1] - [3] . For example, a graphene Mach-Zehnder modulator (MZM) with 2.8Vmm modulation efficiency and 5GHz bandwidth has been demonstrated in the literature [2] . However, one of the challenges for current graphene MZM is graphene’s relatively high insertion loss. Potential solutions have been proposed, such as improving the quality of graphene or operating the device within graphene’s transparency region [4] . Recently, transition metal dichalcogenides (TMDC) have shown a strong electro-refraction effect in the C band, accompanied by only a limited loss increase [3] , which is promising for high efficiency, low loss Mach-Zehnder modulators and switches.