Effect of the spectral broadening of the first Stokes component on the efficiency of a two-stage Raman converter

A two-stage Raman fibre converter (1.089/1.273/1.533 μm) based on a P₂O₅-doped silica fibre is fabricated and studied. The spectral broadening of the first Stokes component is investigated. The Raman converter is simulated numerically. By using the experimental data, the method of Raman converter simulation is improved by taking into account the additional power loss of the first Stokes component. The results of calculations by the improved method are in good agreement with the experiment. It is shown that the additional power loss of the first Stokes component results in a change in the region of the optimal resonator length from 300–600 m to 600–800 m.