Graphene Integrated Microwave Photonics

This paper proposes and analyzes the incorporation of graphene to integrated waveguides and circuits for application to the field of microwave photonics (MWP). We discuss the main optical and electronic properties of graphene in connection to its operation in the optical region of the spectrum, including their tunability by electrical means. We use numerical techniques to evaluate the impact of graphene on the effective index and absorption of the propagating modes in several waveguide designs and use these results to design several fundamental building components that are instrumental in the implementation of several key MWP functionalities including tunable phase-shifters, true time delay lines and Bragg grating filters. Our results suggest that the incorporation of graphene to silicon waveguides can bring important potential benefits, especially in terms of modest power consumption, high tuning speed with respect to other techniques used for current tuneable MWP devices and increased operation bandwidth.