New analytical results on fiber parametric gain and its effects on ASE noise

Parametric gain (PG) in optical fibers may substantially enhance ASE noise, especially in long-haul amplified systems. We present new closed-form analytical results that permit to accurately characterize the effects of PG on ASE noise, as well as the interplay of PG and ASE noise with fiber dispersion in both the anomalous and normal dispersion regions. We introduce the concept of a PG transfer matrix that allows the easy analytical evaluation of ASE noise enhancement over chains of amplified fiber spans.