Power threshold due to parametric gain in dispersion-mapped communication systems

Parametric gain (PG) is investigated in conventional terrestrial transmission systems at 10 Gb/s. The authors present new results that showhowat large signal transmitted power the PG effect strongly differs from the predictions of the standard smallsignal approach, which neglects the noise quadratic and higher order terms in the nonlinear Schrödinger equation. The authors give a new explicit expression of the maximum transmittable power in a dispersion-mapped transmission system impaired by PG and show that such power threshold is due to the inflation of the low frequency portion of the in-phase noise spectrum.