General and effective dynamic gain spectrum control of broadband raman amplifiers with multi-wavelength pumping

An effective feedback algorithm is proposed to dynamically control the gain spectra of multi-wavelength pumped broadband Raman amplifiers. Based on Raman coupling power equations, a simple saturation factor is introduced to achieve the adjusting matrix. By using this method, efficient pump adjustment can be carried out to accomplish wide-range dynamic gain spectrum control (larger than 22 dB dynamic range) as well as automatic gain clamping even for 90 nm bandwidth, highly-saturated RAs. Moreover, this algorithm can be well applied to different fiber types as well as pumping schemes. Some useful guidelines are also demonstrated.