Raman Amplifiers in WDM Systems

Raman amplification provides two approaches to increase the capacity of optical WDM communication that presently utilize the C- and L-bands of erbium doped fiber amplifiers. First, discrete Raman amplifiers can open up wavelength bands outside the erbium window for WDM transmission. Secondly, Raman amplification can be used in conjugation with discrete in-line EDFA's to increase the spectral efficiency of C- and L- band systems.