[4] Chinn S R. Analysis of counter-pumped small-signal fibre Raman amplifiers. Electronics Letters, 1997, 33(7): 607～608
[5] Wang S H,Fan C C. Distributed fiber Raman amplifiers: analytical expression of noise characteristics under complex conditions. Optics Communication, 2001, 198:65～70
[6] Zhang W,Peng J,Liu X,et al.An anlytical expression of equivalent noise figure for distributed fiber Raman amplifiers with Rayleigh scattering.Optical Communications, 2001,198(1～4): 231～236
[7] Mei Jinjie, Liu Deming, Huang Dexiu. Impact of multipath interference on noise figure of fiber Raman amplifiers. Acta Optica Sinica, 2003, 23(6): 652～655
[8] Hartog A H,Gold M P. On the theory of backscattering in single-mode optical fibers. J Lightwave Technol, 1984,2(2):76～82
[9] Parolari P,Marazzi L,Bernardini L,et al. Double Rayleigh scattering noise in lumped and distributed Raman amplifiers. J Lightwave Technol, 2003,21(10): 2224～2228
[10] Haus H A. The noise figure of optical amplifiers. IEEE Photon Technol Lett,1998,10(11):1602～1604
[11] van Deventer M O. Polarization properties of Rayleigh backscattering in single-mode fibers. J Lightwave Technol,1993,11(3): 1895～1899
[12] Winzer P J, Essiambre R J,Bromage J. Combined impact of double-Rayleigh backscatter and amplified spontaneous emission on receiver noise. Proc Optical Fiber Communications Conf, 2002,203(2):734～735
[13] Hansen P B,Eskildsen L,Stentz A J, et al. Rayleigh scattering limitations in distributed Raman pre-amplifiers. IEEE Photon Technol Lett, 1998,10(1): 159～161
[14] Nissov M,Rottwitt K,Kidorf H D,et al. Rayleigh crosstalk in long cascades of distributed unsaturated Raman amplifiers. Electron Lett, 1999,35(12): 997～998
