Applications of dispersion compensating Raman amplifiers

Dispersion compensating fiber (DCF) has seen considerable progress over the last decade and due to its well-controlled dispersion profile, high reliability and passive operation it has become the preferred method for compensating chromatic dispersion in today's optical communication systems. Raman amplification in fibers has found increased use in especially long-haul, high-capacity systems, mainly due to its low noise figure and versatile gain bandwidth. In this paper, we describe how Raman amplification can be used in DCF to realize discrete dispersion-compensating amplifiers, the so-called dispersion compensating Raman amplifier (DCRA). The main focus is on system applications and demonstrated results using DCRAs. These applications include terminal compensation using DCRAs, hybrid amplifiers where the DCRA can be used to extend the dynamic range of existing erbium-doped fiber amplifiers (EDFAs), as well as hybrid EDFA/DCRAs with ultra wide gain bandwidth.