We present a method to determine the fiber chromatic dispersion curve that optimizes the gain band-width and ripple of fiber optical parametric amplifiers. We found that controlling high order dispersion terms a great enhancement of the gain spectrum is achieved. We provide a simulation example of a Photonic Crystal Fiber, designed to control up to the sixth order dispersion parameter that gives 33 dB of gain from 1440 nm to 1600 nm, within 0.2 dB of gain variation. © 2005 IEEE.