Mutual Interactions of Stimulated Raman Scattering and Stimulated Four-Photon Mixing in an Er³⁺-Doped Fiber

The mutual interactions of stimulated Raman scattering (SRS) and stimulated four-photon mixing (SFPM) in an Er³⁺-doped optical fiber have been studied with a tunable pulsed dye laser. Besides normal SRS and SFPM signals, we have observed some new spectral lines. Some of the new lines are attributed to three photon mixing (one from the pump, one from the first-order Stokes and one from SFPM) while the others are assigned to new SRS produced by one of the SFPM signals. The mechanisms of the generation of these new spectral lines are discussed.