Title: Extra-ordinary spectral broadening behavior of laser pulses in graphene-enhanced waveguides

Abstract: Over the past decades, there has been a growing interest in the use of graphene for various photonic applications. Also, the combination of graphene with on-chip waveguides has been extensively explored. While the linear optical properties of graphene are generally well understood, its nonlinear-optical behavior requires further study. In this presentation I will give an overview of our research within the Brussels Photonics group (VUB, Belgium) on the nonlinear-optical response of graphene-enhanced waveguides, with a focus on spectral broadening of short laser pulses propagating inside the waveguides. Our experiments have shown extra-ordinary broadening behavior that originated from saturable free-carrier refraction in the graphene top layer. Furthermore, we have developed a model that explains the apparent discrepancies between the graphene nonlinearity values reported by different groups in recent years.

About the speaker: Nathalie Vermeulen is a tenure track professor at the Faculty of Engineering of the Vrije Universiteit Brussel (VUB), Belgium. She leads the Nonlinear Optics team within the Brussels Photonics (B-PHOT) research group. Nathalie received the M.Sc. degree in electrical engineering with majors in photonics in 2004 and obtained her PhD in 2008, both from VUB. In 2013 she acquired a Starting Grant from the European Research Council. Nathalie also coordinated an EU-funded Future and Emerging Technologies project for ‘Young Explorers’ and now serves as a principal investigator in a Belgian Excellence of Science project. Her current research activities are focused on nonlinear photonic integrated circuits enhanced with 2D materials.