Hybrid optical amplifiers for flexible development in long reach optical access system

In this paper the authors have investigated the performance improvement in long reach optical access system with hybrid optical amplifiers. The apparent options of optical amplification in wavelength division multiplexing systems include the distributed Raman amplifiers, erbium doped fiber amplifiers, and semiconductor optical amplifiers. In our case distributed Raman amplifier is located at the mid-span reach extender which allows for remote amplification in passive network nodes by distributing a Raman pump together with the data signals. In the case of only distributed Raman amplifier in long reach optical access system wavelength division multiplexing exploitation is inefficient. Combining the advantages of different amplifiers allows fast gain dynamics, simultaneous large bandwidth amplification, and the ability to provide gain at any wavelength. Degradation of optical signal quality is evaluated in 10 Gbit/s long reach wavelength division multiplexing optical access system with hybrid distributed Raman-erbium doped fiber amplifier and distributed Raman-semiconductor optical amplifier.