title: A highly efficient thermo-optic microring modulator assisted by graphene.
abstract: Graphene's remarkable electrical and optical properties afford great potential for constructing various optoelectronic devices, including modulators, photodetectors and pulse lasers. In particular, graphene-based optical modulators were demonstrated to be featured with a broadband response, small footprint, ultrafast speed and CMOS-compatibility, which may provide an alternative architecture for light-modulation in integrated photonic circuits. While on-chip graphene modulators have been studied in various structures, most of them are based on a capacitance-like configuration subjected to complicated fabrication processes and providing a low yield of working devices. Here, we experimentally demonstrate a new type of graphene modulator by employing graphene's electrical and thermal properties, which can be achieved with a simple fabrication flow. On a graphene-coated microring resonator with a small active area of 10 μm(2), we have obtained an effective optical modulation via thermal energy electrically generated in a graphene layer. The resonant wavelength of the ring resonator shifts by 2.9 nm under an electrical power of 28 mW, which enables a large modulation depth of 7 dB and a broad operating wavelength range of 6.2 nm with 3 dB modulation. Due to the extremely high electrical and thermal conductivity in graphene, the graphene thermo-optical modulator operates at a very fast switching rate compared with the conventional silicon thermo-optic modulator, i.e. 10%-90% rise (90%-10% fall) time of 750 ns (800 ns). The results promise a novel architecture for massive on-chip modulation of optical interconnects compatible with CMOS technology.
authors.affiliation: Institute of Functional Nano and Soft Materials (FUNSOM), Jiangsu Key Laboratory for Carbon-Based Functional Materials and Devices, and Collaborative Innovation Center of Suzhou Nano Science and Technology, Soochow University, Suzhou 215123, P. R. China. qlbao@suda.edu.cn.
authors.forename: Sheng
authors.initials: S
authors.lastname: Gan
authors.forename: Chuantong
authors.initials: C
authors.lastname: Cheng
authors.forename: Yaohui
authors.initials: Y
authors.lastname: Zhan
authors.forename: Beiju
authors.initials: B
authors.lastname: Huang
authors.forename: Xuetao
authors.initials: X
authors.lastname: Gan
authors.forename: Shaojuan
authors.initials: S
authors.lastname: Li
authors.forename: Shenghuang
authors.initials: S
authors.lastname: Lin
authors.forename: Xiaofeng
authors.initials: X
authors.lastname: Li
authors.forename: Jianlin
authors.initials: J
authors.lastname: Zhao
authors.forename: Hongda
authors.initials: H
authors.lastname: Chen
authors.forename: Qiaoliang
authors.initials: Q
authors.lastname: Bao