Waveguide-integrated optical modulators with two-dimensional materials

Waveguide-integrated optical modulators are indispensable for on-chip optical interconnects and optical computing. To cope with the ever-increasing amount of data being generated and consumed, ultrafast waveguide-integrated optical modulators with low energy consumption are highly demanded. In recent years, two-dimensional (2D) materials have attracted a lot of attention and have provided tremendous opportunities for the development of high-performance waveguide-integrated optical modulators because of their extraordinary optoelectronic properties and versatile compatibility. This paper reviews the state-of-the-art waveguide-integrated optical modulators with 2D materials, providing researchers with the developing trends in the field and allowing them to identify existing challenges and promising potential solutions. First, the concept and fundamental mechanisms of optical modulation with 2D materials are summarized. Second, a review of waveguide-integrated optical modulators employing electro-optic, all-optic, and thermo-optic effects is provided. Finally, the challenges and perspectives of waveguide-integrated modulators with 2D materials are discussed.