Graphene-based integrated photonics for next-generation datacom and telecom

Graphene is an ideal material for optoelectronic applications. Its photonic properties give several advantages and complementarities over Si photonics. For example, graphene enables both electro-absorption and electro-refraction modulation with an electro-optical index change exceeding 10−3. It can be used for optical add–drop multiplexing with voltage control, eliminating the current dissipation used for the thermal detuning of microresonators, and for thermoelectric-based ultrafast optical detectors that generate a voltage without transimpedance amplifiers. Here, we present our vision for graphene-based integrated photonics. We review graphene-based transceivers and compare them with existing technologies. Strategies for improving power consumption, manufacturability and wafer-scale integration are addressed. We outline a roadmap of the technological requirements to meet the demands of the datacom and telecom markets. We show that graphene-based integrated photonics could enable ultrahigh spatial bandwidth density, low power consumption for board connectivity and connectivity between data centres, access networks and metropolitan, core, regional and long-haul optical communications. Graphene-integrated photonics is a platform for wafer-scale manufacturing of modulators, detectors and switches for next-generation datacom and telecom systems. This Review describes how these functions can be achieved with graphene layers placed on top of optical waveguides, acting as passive light guides, thus simplifying the current technology. In addition, a roadmap of the technological requirements for the datacom and telecom markets is presented.