Wide-bandwidth and high-gain fiber optical parametric amplifiers (OPAs) have been demonstrated recently. Their application as all-optical wavelength converters has been hampered by pump-induced converted-signal spectrum broadening,due to the required pump phase modulation. In this paper, we theoretically investigate and experimentally demonstrate a technique to cancel the converted-signal broadening by using four-wave mixing (FWM) or parametric amplification with two pumps phase-modulated 180° out of phase. The resulting converted-signal quality is comparable to that of the output signal.
Min-Chen Ho, Michel E. Marhic, K. Y. Kenneth Wong, and Leonid G. Kazovsky, "Narrow-Linewidth Idler Generation in Fiber Four-Wave Mixing and Parametric Amplification by Dithering Two Pumps in Opposition of Phase," J. Lightwave Technol. 20, 469- (2002)