title: Ultrafast all-optical graphene modulator.
abstract: Graphene is an optical material of unusual characteristics because of its linearly dispersive conduction and valence bands and the strong interband transitions. It allows broadband light-matter interactions with ultrafast responses and can be readily pasted to surfaces of functional structures for photonic and optoelectronic applications. Recently, graphene-based optical modulators have been demonstrated with electrical tuning of the Fermi level of graphene. Their operation bandwidth, however, was limited to about 1 GHz by the response of the driving electrical circuit. Clearly, this can be improved by an all-optical approach. Here, we show that a graphene-clad microfiber all-optical modulator can achieve a modulation depth of 38% and a response time of ∼ 2.2 ps, limited only by the intrinsic carrier relaxation time of graphene. This modulator is compatible with current high-speed fiber-optic communication networks and may open the door to meet future demand of ultrafast optical signal processing.
authors.affiliation: State Key Laboratory of Modern Optical Instrumentation, Department of Optical Engineering, Zhejiang University , Hangzhou 310027, China.
authors.forename: Wei
authors.initials: W
authors.lastname: Li
authors.forename: Bigeng
authors.initials: B
authors.lastname: Chen
authors.forename: Chao
authors.initials: C
authors.lastname: Meng
authors.forename: Wei
authors.initials: W
authors.lastname: Fang
authors.forename: Yao
authors.initials: Y
authors.lastname: Xiao
authors.forename: Xiyuan
authors.initials: X
authors.lastname: Li
authors.forename: Zhifang
authors.initials: Z
authors.lastname: Hu
authors.forename: Yingxin
authors.initials: Y
authors.lastname: Xu
authors.forename: Limin
authors.initials: L
authors.lastname: Tong
authors.forename: Hongqing
authors.initials: H
authors.lastname: Wang
authors.forename: Weitao
authors.initials: W
authors.lastname: Liu
authors.forename: Jiming
authors.initials: J
authors.lastname: Bao
authors.forename: Y Ron
authors.initials: YR
authors.lastname: Shen