Numerical achievement of high and flat gain using Er-Yb co-doped fiber/Raman hybrid optical amplifier

Abstract

A novel hybrid optical amplifier is proposed for 100 × 10 Gb/s dense wavelength division multiplexed (DWDM) system. The amplifier consists of a combination of Er-Yb co-doped fiber amplifier (EYDFA) with backward-propagating multi-pump Raman amplifier. A flat gain of >26 dB is achieved, over a wavelength range of 1545–1565 nm. The scheme works at 1 mW optimum input power per channel. Gain ripple of 1.37 dB and noise figure (NF) of <4.5 dB is observed. Anyhow, for higher input powers up to 10 mW, an increase in gain ripple up to 7.59 dB and NF up to 12.04 dB is observed. The effects of varying various parameters, like EYDFA pump wavelength, EYDFA length, Er/Yb concentrations and Raman length are also investigated. The obtained high and flat gain, along with the low NF, lesser bit error rate and high Q-factor, justifies the usefulness of proposed amplifier for applications in long-haul DWDM systems.