Spectral characteristics of Raman gain were theoretically investigated for step index silica optical fibers with various GeO2 concentrations. The evolution of stimulated Raman scattering cross sections for the 1st and the 2nd Stokes shifts along fiber lengths were rigorously analyzed using the Raman frequency modeling, for the first time. By the energy transfer from the 1st to the 2nd Stokes shift, saturation in the Raman gain was observed and the onset of the energy transfer was theoretically predicted. Optimal fiber lengths for Raman amplifiers where the 1st Stokes power reaches the maximum were calculated for arbitrary GeO2 concentration and pumping power.
Bibliographical noteFunding Information:
This work was partly supported by UFON, an ERC program sponsored by KOSEF, and BK21 program, supported by MOE in Korea.
All Science Journal Classification (ASJC) codes
- Electronic, Optical and Magnetic Materials
- Atomic and Molecular Physics, and Optics
- Physical and Theoretical Chemistry
- Electrical and Electronic Engineering