Plasmonics for optical communications: The use of graphene for optimizing coupling efficiency

Application of plasmonics in optical communications has recently attracted significant research interest in the hope of overcoming the big mismatch between the footprints of electronic and photonic integrated circuits. This hope is based on the unique properties of the plasmonic devices, such as the confinement of light into subwavelength dimension. which enables breaking the diffraction limit and creating a strong field enhancement and the potential to combine the best properties of both electronic and photonic words thanks to the natural interaction between photons and electrons in excitation of surface plasmon polaritons (SPPs). Such a breakthrough would lead to the development of new types of opto-electronic devices. One the main problems to be solved for this application to succeed is the coupling efficiency of incident light. This paper reviews our investigation of the various approaches to increasing the coupling efficiency and shows how the use of graphene can significantly improve this efficiency.