Performance evaluation and comparative study of novel high and flat gain C plus L band Raman plus EYDFA co-doped fibre hybrid optical amplifier with EYDFA only amplifier for 100 channels SD-WDM systems

In this work, we present a Raman + erbium-ytterbium co-doped fiber amplifier (EYDFA) hybrid optical amplifier (HOA) for C + L band operation in super dense wavelength division multiplexing systems (SD-WDM). The performance of the proposed HOA has been studied for a 100 channels SD-WDM system, carrying 80 Gb/s of data with a channel spacing of 0.2 nm and a wavelength range of 1525-1625 nm. Optimizing the performance of the amplifier, results in the achievement of maximum gain and Q-Factor of 41.8 dB and 15.5 respectively with gain variation ratio less than 1.62 using pump wavelength of 1056 nm for operation in C + L band. The performance of the proposed HOA has also been compared with EYDFA only amplifier for similar system specifications using EYDFA pump wavelength of 1480 nm. Highest flat gain of 44.3 and 45.2 dB and Q-factor of 14 and 11.38 have been observed with a gain variation ratio less than 0.22 over a wavelength range of 1535-1567 nm for HOA and EYDFA only amplifier respectively. The better results have been obtained in terms of Q-factor and GVR in case of HOA as compared to EYDFA only amplifier. High gain; good Q-factor along with improved gain flatness achieved in case of HOA confirms its viability for applications in broadband long haul SD-WDM systems.