Analytic Representation of Stokes Noise Spectrum and Raman Gain Profile in Silica Fiber

The fundamental parameters of a number of Raman photonics devices are formed by the gain profile of active fiber and its Stokes noise spectra. The high accuracy results of numerical approximation of the Raman gain profile in $\text{TiO}_{2}$ doped single mode silica fiber and its noise spectrum were obtained in our work by application of two independent methods. The spectroscopic approach was realized in the form of multimode Gaussian decomposition. The rational approximation with enough high order (M=12) was applied too. The high fitting precision no worse 0.1 % was demonstrated in both approximation methods. The simple analytic form of our modeling results may be significant advantages in application to the design of many modern photonic devices based on fiber nonlinear optics.