Abstract
This paper reviews recent progress in broadband Raman amplifiers for WDM applications. After discussing the fundamentals of Raman amplifiers, basic characteristics of multi-wavelength pumped Raman amplifiers are presented. The design procedure of multi-wavelength pumped Raman amplifiers is summarizedwith respect to the pumping wavelength and power allocation, which are explained by superposition rule and pumpto-pump energy transfer, respectively. The comparison between simulated and experimental results is presented to illustrate the validity of the procedure. The design and demonstration of outstanding performances such as 100nm of flat gain bandwidth and 0.1dB flatness over 80nm are also presented.
