Self-similar propagation of parabolic pulses in normal-dispersion fiber amplifiers

Abstract

Pulse propagation in high-gain optical fiber amplifiers with normal group-velocity dispersion has been studied by self-similarity analysis of the nonlinear Schrödinger equation with gain. For an amplifier with a constant distributed gain, an exact asymptotic solution has been found that corresponds to a linearly chirped parabolic pulse that propagates self-similarly in the amplifier, subject to simple scaling rules. The evolution of an arbitrary input pulse to an asymptotic solution is associated with the development of low-amplitude wings on the parabolic pulse whose functional form has also been found by means of self-similarity analysis. These theoretical results have been confirmed with numerical simulations. A series of guidelines for the practical design of fiber amplifiers to operate in the asymptotic parabolic pulse regime has also been developed.

Strictly all-fiber picosecond ytterbium fiber laser utilizing chirped-fiber-Bragg-gratings for dispersion control

“…7. The combined action of gain, nonlinearity and normal dispersion along the amplification stages should result in the generation of nearly linearly chirped parabolic pulses [18]. This was experimentally observed, as can be confirmed from the agreement of the solid measured autocorrelation trace and the dotted theoretical parabolic-pulse autocorrelation trace in Fig.…”

Soliton–similariton fibre laser

“…In addition to the vast literature on optical solitons 18 , optical similaritons have recently emerged as a new class of nonlinear waves 19 . Other researchers [20][21][22][23] have demonstrated their existence in fibre amplifiers. These results have extended earlier predictions of parabolic pulse propagation in passive fibres by Anderson and colleagues 24 and experiments on amplification at normal dispersion 25 .…”

Ultrashort pulse formation and evolution in mode-locked fiber lasers

“…It is also well-known that for a fast convergence to the self-similar evolution in the SMF inside the cavity, the pulse parameters of the pulse entering the SMF have to be optimum. For passive fibers such a condition was discussed by [9]. It is therefore clear that only a limited range of intra-cavity pulse conditions lead to pulses evolving truly self-similar in the SMF and explains the small region of equal kurtosis in the temporal and spectral domain.…”