Transient effects in gain-clamped discrete Raman amplifier cascades

This letter describes the dynamic characteristics of all-optically gain clamped discrete Raman amplifier chains. Amplifier cascades are analyzed under channels add/drop conditions in large bandwidth WDM metro-core applications. Numerical results show that the long Raman fiber length does not allow instantaneous gain clamping giving rise to wide power oscillations in long Raman amplifier chains. A possible way to limit this detrimental effect is suggested and numerically demonstrated.