Gain fluctuations in in optical fiber parametric amplifiers

We analyzed the dependence of fiber optical parametric amplifiers gain as a function on the relative phase of the three input waves: pump, signal and idler. Signal amplification is strongly phase dependent for small (<10 dB) signal-to-idler power ratio. In the case where the input idler is an optical noise field, gain fluctuations /spl ges/1 dB are expected for signal-to-idler input ratios /spl les/20 dB.