Influence of graphene on quality factor variation in a silicon ring resonator

Selectively patterned graphene is integrated onto a silicon ring resonator to investigate the quality factor (Q factor) variation. The Q factor sharply decreases from 7900 to 1200 as the patterned graphene length increases from 0 to 20 mu m. A numerical estimation, which takes into account optical absorption by graphene, shows an exponential damping of the Q factor with increasing graphene length and is consistent with the experimental result. We expect these fundamental characterizations to be helpful in developing graphene-integrated silicon photonics applications. (C) 2014 AIP Publishing LLC.