The gain spectrum character under Raman scattering and parametric amplification

Abstract

According to the nonlinear coupled equation under the joint action of Raman scattering and parametric amplification when the optical pulse propagats in the birefringent fiber, based on Lorentzian model of parallel Raman gain spectrum, the gain spectrum is obtained by combining Raman scattering and parametric amplification when the pump wave polarization direction is along the two orthogonal birefringence axes. The gain spectrum is discussed as a function of input parameters (input power, the group velocity mismatch) in different dispersion regimes. The result shows that the balance between non-linearity and dispersion is destructed by Raman scattering. Stokes and anti-stokes gain spectrum are asymmetric because of Raman effect. The structure of gain spectrum is confirmed when input power is constant. The intensity and width of gain spectrum change with dispersion and nonlinear parameter.