title: Generation of optical frequency combs in a fiber-ring/microresonator laser system.
abstract: We propose and experimentally demonstrate a simple scheme for generating optical frequency combs (OFCs) in a fiber-ring/microresonator laser system. The ultrahigh Q whispering gallery mode microresonator is employed both as a mode reflection mirror to generate erbium lasing and as a Kerr-nonlinearity initiator that introduces optical parametric oscillation signals to form OFCs. By controlling the coupling position between the fiber taper and microresonator, optimizing the fiber polarization, as well as the pump power from a 974 nm laser diode (LD), versatile OFCs can be tuned out from single-wavelength states. The OFCs have single, multiple, or combined free spectral ranges. In addition, a Raman-gain-assisted OFC is also observed with a bandwidth of ∼230  nm. This LD-pumped and multifunctional laser system could find applications in precision spectroscopy, biochemical sensing, and optical fiber communication systems.
authors.forename: Changlei
authors.initials: C
authors.lastname: Guo
authors.forename: Kaijun
authors.initials: K
authors.lastname: Che
authors.forename: Huiying
authors.initials: H
authors.lastname: Xu
authors.forename: Pan
authors.initials: P
authors.lastname: Zhang
authors.forename: Deyu
authors.initials: D
authors.lastname: Tang
authors.forename: Changyan
authors.initials: C
authors.lastname: Ren
authors.forename: Zhengqian
authors.initials: Z
authors.lastname: Luo
authors.forename: Zhiping
authors.initials: Z
authors.lastname: Cai