An alternative structure using third-order Raman amplification based on ultralong fiber lasers (UL-FLs) is investigated numerically to further improve the quasi-lossless transmission performance. The performance comparisons on flatness of signal distribution, optical signal–noise ratio (OSNR), and noise figure (NF) among first-order, second-order, and third-order Raman pumping based on UL-FLs are discussed numerically. The results display that the gain distribution is pushed more uniformly along UL-FLs using third-order Raman pumping, which is very useful to further extend the quasi-lossless midspan distance. For transparency transmission, enhanced quasi-lossless transmission could be achieved without sacrifice to OSNR and NF. We also analyze the transmission dynamics of loss-managed fundamental solitons for different pumping configurations. The amplifier span and transmission quality are improved considerably, even for lower dispersion lengths, by employing the proposed scheme.
© 2012 Optical Society of America
Fiber Optics and Optical Communications
Original Manuscript: September 15, 2011
Revised Manuscript: December 17, 2011
Manuscript Accepted: December 27, 2011
Published: March 30, 2012
Xin-Hong Jia, Yun-Jiang Rao, Zi-Nan Wang, Wei-Li Zhang, Zeng-Ling Ran, Kun Deng, and Zi-Xin Yang, "Detailed theoretical investigation on improved quasi-lossless transmission using third-order Raman amplification based on ultralong fiber lasers," J. Opt. Soc. Am. B 29, 847-854 (2012)