Enhancement of hybrid serial fiber amplifier based on higher order raman scattering

A broadband serial hybrid fiber amplifier (SHFA) schemes based on second order Raman scattering is demonstrated using OptiSystems 14. Employing of second order Raman scattering can provide an amplification bandwidth and generate a spectrally flat gain enhancement in WDM transmission systems without the need for any gain flatting filters technique. The thesis carries out the design, optimization, and development of a wideband hybrid fiber amplifier covering wavelength of 1524 to 1622 nm. The proposed design combines two gain mediums; Erbium-doped fiber amplifier (EDFA) as linear gain that consist of 3 m EDF with 1480 nm pump power, and the nonlinear gain of Raman fiber amplifier (RFA) which provided by 7 km dispersion compensation fiber (DCF) and two Raman pump units of RP1 and RP2. The performance of the system is analyzed and discussed in term of overall gain level, amplification bandwidth, gain dynamic range, and the noise figure. Wide flat gain bandwidth of 98 nm (1524-1622) that has 19.6 dB gain average is presented at small input signal power of -30 dBm. In addition, relatively low gain variation about 2.71 dB and an acceptable 5.12 dB noise figure are achieved at the same input signal power.