  Operation of a degenerate dual-pump phase sensitive amplifier (PSA) is
thoroughly numerically investigated using a multi-wave model, taking into
account high-order waves associated with undesired four-wave mixing (FWM)
processes. More accurate phase-sensitive signal gain spectra are obtained
compared to the conventional 3-wave model, leading to the precise optimization
of the pump configuration in a dual-pump PSA. The signal gain spectra, as well
as the phase sensitivity, are obtained and interpreted by investigating the
dominant FWM processes in terms of corresponding phase matching. Moreover, the
relation between dispersion slope and gain spectra is revealed, permitting the
application-oriented arbitrary tailoring of the gain spectra by manipulating
the dispersion profile and pump wavelength allocation.
