CMOS-Compatible WS2-Based All-Optical Modulator

Abstract

Two-dimensional materials are compatible with silicon complementary metal-oxide semiconductor processes. As such, the integration of two-dimensional materials with silicon-based semiconductors could lead to an amalgamation of the beneficial properties of both silicon and the two-dimensional material thereby facilitating improved performance. Single-layer transition metal dichalcogenide materials like MoS2, MoTe2 and WS2 are characterized by direct band gaps and possess high emission efficiencies. These materials are, therefore, perfectly suited for ameliorating the optical emission inadequacies of silicon-based-materials. In this study, we integrate WS2 with a silicon-based silicon-nitride waveguide to modulate a 532-nm pump light source, and successfully modulate and amplify an optical signal at 640 nm. Compared to other modulators based on two-dimensional materials, e.g., graphene, the proposed WS2-based modulator theoretically incurs lower losses and exhibits higher contrast levels and signal-to-noise ...