Q penalties due to pump phase modulation and pump RIN in fiber optic parametric amplifiers with non-uniform dispersion

Abstract

We present an experimental and numerical investigation of the quality factor degradation (ΔQ) due to pump phase modulation and pump relative intensity noise (RIN) in single- and double-pumped fiber optical parametric amplifiers (FOPAs). These penalties are investigated in FOPAs constructed with fibers having constant and randomly varying zero dispersion wavelength (λ0) along the fiber.We show that pump phase modulation in uniform fibers (constant λ0) produces large Q penalties, while in fibers with variations of λ0, these penalties can be strongly reduced in both, single and double-pumped FOPAs. We also show that Q penalties due to pump phase modulation tend to disappear in FOPAs made with very short fibers (L<0.1km) and very low dispersion slope (S0<0.002ps/nm2-km).The Q penalties due to pump RIN, which for typical FOPA parameters are much smaller than those due to pump phase modulation, are also reduced in non-uniform fibers (varying λ0), but do not depend on fiber length neither on fiber dispersion slope.