title: Initial conditions for dark soliton generation in normal-dispersion fiber lasers.
abstract: We report results of numerical simulations on the various initial conditions for dark soliton generation in an all-normal-dispersion fiber laser. All the dark solitons generated are odd dark solitons. Differently from the dark soliton generation in fibers, where an arbitrary dip could evolve into a dark soliton, it is found that the dark soliton can originate only from an initial dip with a certain parameter requirement. A bright pulse with either a hyperbolic secant square, Gaussian, or Lorentz profile can be developed into a dark soliton, provided that the parameters of the initial bright pulse are selected. Dark solitons can be generated in fiber lasers only if there is a phase jump, and this phase jump can be maintained and evolve to π during the pulse evolution.
authors.forename: Y Q
authors.initials: YQ
authors.lastname: Ge
authors.forename: J L
authors.initials: JL
authors.lastname: Luo
authors.forename: L
authors.initials: L
authors.lastname: Li
authors.forename: X X
authors.initials: XX
authors.lastname: Jin
authors.forename: D Y
authors.initials: DY
authors.lastname: Tang
authors.forename: D Y
authors.initials: DY
authors.lastname: Shen
authors.forename: S M
authors.initials: SM
authors.lastname: Zhang
authors.forename: L M
authors.initials: LM
authors.lastname: Zhao