title: All-optical tuning of a magnetic-fluid-filled optofluidic ring resonator.
abstract: An all-optical tunable optofluidic ring resonator (OFRR) is proposed and experimentally demonstrated. The all-optical control of a silica microresonator is highly attractive, but it is difficult to realize because of the relatively weak Kerr effect and the absence of a plasma dispersion effect of silica. Here, we infuse a silica microcapillary-based optofluidic ring resonator with a magnetic fluid, into which pump light is injected by a fiber taper. Iron oxide nanoparticles dispersed in the magnetic fluid produce a strong pump light absorption, and this leads to a resonance shift of the silica microresonator due to the photothermal effect. To the best of our knowledge, this is the first scheme for all-optical tuning of an OFRR. A tuning sensitivity of up to 0.15 nm mW(-1) and a tuning range of 3.3 nm are achieved. With such excellent performance, the magnetic-fluid-filled OFRR has great potential in filtering, sensing, and signal processing applications.
authors.affiliation: Wuhan National Laboratory for Optoelectronics, Huazhong University of Science and Technology, Wuhan 430074, China. lshi@mail.hust.edu.cn xlzhang@mail.hust.edu.cn.
authors.forename: Yang
authors.initials: Y
authors.lastname: Liu
authors.forename: Lei
authors.initials: L
authors.lastname: Shi
authors.forename: Xinbiao
authors.initials: X
authors.lastname: Xu
authors.forename: Ping
authors.initials: P
authors.lastname: Zhao
authors.forename: Zheqi
authors.initials: Z
authors.lastname: Wang
authors.forename: Shengli
authors.initials: S
authors.lastname: Pu
authors.forename: Xinliang
authors.initials: X
authors.lastname: Zhang