In this paper we report phase modulation obtained by inducing a capacitive charge on graphene layers embedded in the core of a waveguide. There is a biasing regime in which graphene absorption is negligible but large index variations can be achieved with a voltage-length product as small as VπLπ≃0.04\,V\,cm . Examples of phase induced changes are computed for straight waveguides and for microring resonators showing the possibility to implement several optoelectronic functionalities as modulators, tunable filters, and switches.
@article{arxiv.1304.6596,
title = {Graphene Based Optical Phase Modulation},
author = {Michele Midrio and Paola Galli and Marco Romagnoli and Lionel C. Kimerling and Jurgen Michel},
journal= {arXiv preprint arXiv:1304.6596},
year = {2013}
}