Compensation of the soliton self-frequency shift with phase-sensitive amplifiers

Abstract

We analyze the effect of Raman scattering and higher-order dispersion on the propagation of short (1-ps) pulses in a nonlinear optical fiber in which the loss is balanced by a periodic chain of phase-sensitive, degenerate parametric amplifiers. The analysis shows that the Raman scattering does not induce a continuous frequency downshift on the pulse but only a small, finite frequency shift. Pulse propagation is governed by a nonlinear fourth-order evolution equation that admits stable solutions that propagate with a small, constant, inverse velocity in the group-volocity rest frame.