Optimization for various schemes of distributed fibre Raman amplifiers

A fast and stable numerical method for solving the model equations of distributed fibre Raman amplifiers is proposed. This method can increase the computing speed by more than five times compared to the classical Dormand?Prince method. In this paper, on the basis of the proposed method and genetic algorithm, the signal gain spectrum and corresponding optical signal-to-noise ratio (OSNR) for counter-?and bi-directional multi-pump Raman amplifiers are optimized and compared. The optimized results show that (1)?bi-directionally pumping configurations with proper forward pump diodes can effectively decrease the gain ripple and the OSNR ripple and equalize the OSNR tilt in comparison with pure backward pumping configurations; (2)?the gain spectrum and noise performance can be availably improved by means of increasing the pump number. The simulations demonstrate that, when optimizing bi-directional multi-pump configurations, (1)?there are multiple global or near-global maxima for the signal gain spectrum; (2)?different bi-directional pump schemes have different gain ripple and noise performance.

[1]  P. Poggiolini,et al.  On the optimization of hybrid Raman/erbium-doped fiber amplifiers , 2001, IEEE Photonics Technology Letters.

[2]  S. Namiki,et al.  Broadband lossless DCF using Raman amplification pumped by multichannel WDM laser diodes , 1998 .

[3]  T. Sylvestre,et al.  Cascaded Raman generation in optical fibers: influence of chromatic dispersion and Rayleigh backscattering. , 2004, Optics letters.

[4]  S. Namiki,et al.  Ultrabroad-band Raman amplifiers pumped and gain-equalized by wavelength-division-multiplexed high-power laser diodes , 2001 .

[5]  Byoungho Lee,et al.  A fast and stable method for Raman amplifier propagation equations. , 2003, Optics express.

[6]  Ari T. Friberg,et al.  The impact of pump polarization on the polarization dependence of the Raman gain due to the breaking of a fibre's circular symmetry , 2004 .

[7]  S. Gray,et al.  A method for progressive optimization of pump power and wavelengths for Raman amplification , 2004, IEEE Photonics Technology Letters.

[8]  Byoungho Lee,et al.  Optimal design for ultra-broad-band amplifier , 2003 .

[9]  Analytic modelling of high-gain ytterbium-doped fibre amplifiers , 2002 .

[10]  G. Jacobsen,et al.  Polarization dependence of gain in discrete Raman amplifiers with dispersion compensating fibres , 2002 .

[11]  Byoungho Lee,et al.  Effective shooting algorithm and its application to fiber amplifiers. , 2003, Optics express.

[12]  J. Simon,et al.  Gain dynamics studies of a semiconductor optical amplifier , 2002 .