title: Graphene coated ZnO nanowire optical waveguides.
abstract: We report the fabrication and characterization of freestanding graphene coated ZnO nanowires (GZNs) for optical waveguiding. The GZNs are fabricated using a tape-assist transfer under micromanipulation. Owing to the deep-subwavelength diameter and high index contrast of the ZnO nanowire waveguide, light-graphene interaction is significantly enhanced by the strong surface optical fields, resulting in a linear absorption as high as 0.11 dB/µm in a 606-nm-diameter GZN at 1550-nm wavelength. Launched by 1550-nm-wavelength femto-second pulses, a 475-nm-diameter GZN with a graphene coating length of merely 24 µm exhibits evident nonlinear saturable absorption with a peak power threshold down to 1.3 W. In addition, we also demonstrate a transmission modulation for 1550-nm-wavelength signal with a 590-nm-diameter GZN, showing the possibility of using GZN waveguides as nanoscale bulding blocks for nanophotonic devices.
authors.forename: Bigeng
authors.initials: B
authors.lastname: Chen
authors.forename: Chao
authors.initials: C
authors.lastname: Meng
authors.forename: Zongyin
authors.initials: Z
authors.lastname: Yang
authors.forename: Wei
authors.initials: W
authors.lastname: Li
authors.forename: Shisheng
authors.initials: S
authors.lastname: Lin
authors.forename: Tingyi
authors.initials: T
authors.lastname: Gu
authors.forename: Xin
authors.initials: X
authors.lastname: Guo
authors.forename: Delong
authors.initials: D
authors.lastname: Wang
authors.forename: Shaoliang
authors.initials: S
authors.lastname: Yu
authors.forename: Chee Wei
authors.initials: CW
authors.lastname: Wong
authors.forename: Limin
authors.initials: L
authors.lastname: Tong