Abstract

Currently, solitons with a minimum duration of approximately 50 fs are obtained in optical fibers. Adiabatic compression of solitons in fibers with slowly decreasing dispersion (FSDD) is promising for the generation of high-quality pulses with a shorter duration in the near IR.¹ New effects arise at the femtosecond pulse propagation in fibers. For the theoretical description of such a propagation, the traditional nonlinear Schrödinger equation needs to be modified. In recent papers^2-4 nonlinear equations were considered, and the real part as well as the imaginary part of the third-order nonlinear susceptibility χ⁽³⁾ was taken into account. In Refs. 3 and 4 the real spectral dependence χ⁽³⁾ (ω) is discussed. In this paper we discuss the model that, in addition to the effects mentioned above, takes into account the Stokes losses associated with the material excitation during the Raman self-scattering effect and the dependence of the third-order nonlinear effects on the radiation frequency.

© 1990 Optical Society of America