10.1021/acs.nanolett.5b00630.s001 Yunhong Ding Yunhong Ding Xiaolong Zhu Xiaolong Zhu Sanshui Xiao Sanshui Xiao Hao Hu Hao Hu Lars Hagedorn Frandsen Lars Hagedorn Frandsen N. Asger Mortensen N. Asger Mortensen Kresten Yvind Kresten Yvind Effective Electro-Optical Modulation with High Extinction Ratio by a Graphene–Silicon Microring Resonator American Chemical Society 2015 control optoelectronic properties graphene voltage High Extinction Ratio interaction ultralarge absorption bandwidth modulation depth microring novel optoelectronic applications thanks device dB 2015-07-08 00:00:00 Journal contribution https://acs.figshare.com/articles/journal_contribution/Effective_Electro_Optical_Modulation_with_High_Extinction_Ratio_by_a_Graphene_Silicon_Microring_Resonator/2203795 Graphene opens up for novel optoelectronic applications thanks to its high carrier mobility, ultralarge absorption bandwidth, and extremely fast material response. In particular, the opportunity to control optoelectronic properties through tuning of the Fermi level enables electro-optical modulation, optical–optical switching, and other optoelectronics applications. However, achieving a high modulation depth remains a challenge because of the modest graphene-light interaction in the graphene–silicon devices, typically, utilizing only a monolayer or few layers of graphene. Here, we comprehensively study the interaction between graphene and a microring resonator, and its influence on the optical modulation depth. We demonstrate graphene–silicon microring devices showing a high modulation depth of 12.5 dB with a relatively low bias voltage of 8.8 V. On–off electro-optical switching with an extinction ratio of 3.8 dB is successfully demonstrated by applying a square-waveform with a 4 V peak-to-peak voltage.