Waveguide design parameters impact on absorption in graphene coated silicon photonic integrated circuits

Abstract

In this paper, we propose a new way of estimating the absorption in graphene coated silicon wire waveguides based on a self-developed, modified 2D Finite Difference Method, and use it to obtain a detailed absorption dependency of the waveguide design. For the first time, we observe peaks in the TM mode absorption curves, as well as the reversals of the dominantly absorbed mode with waveguide design variation, both of which have not been predicted previously theoretically, but have been implied through experimental results. We also provide a qualitative explanation of our novel numerical results, and explain how these results can be utilized in optimization of various graphene based integrated devices like optical modulators, photodetectors and optical polarizers.