One-pump fiber optical parametric amplifier in presence of dispersion fluctuations: impact of fourth-order dispersion...

The impact of random dispersion fluctuations on the gain and saturation behavior of a one-pump fiber optical parametric amplifier (1-P FOPA) in the presence of fourth-order dispersion coefficient (β₄) is investigated. Three coupled amplitude equations with fiber losses are solved numerically for the calculation of the pump, signal, and idler. The performances of 1-P FOPA are also analyzed with variation of dispersion fluctuation amplitude (σ) and correlation length (L_c). Based on the numerical results, it is found that the gain spectra and saturation curves exhibit some differences when β₄ is considered. In comparison with the case where β₄ is ignored, the peak gain remains the same, but the 3 dB bandwidth increases when β₄ exists. Another notable difference is that the saturation power is shifted to lower or higher values, depending on the σ and L_c parameters. In general, the peak gain reduces as σ increases, and the peak gain reduction is greater for the case of shorter L_c. The numerical analysis is probably useful, especially for the case where the signal wavelength is detuned far from the pump wavelength.