Pakarzadeh H, Othman N, Tay K G, Cholan N A
Appl Opt. 2022 Jan 1;61(1):308-315. doi: 10.1364/AO.445060.
Fiber optical parametric amplifiers (FOPAs) operating based on four-wave mixing (FWM) are versatile devices with increasing applications in optical communication systems. In this paper, the effects of dispersion fluctuations on the performance of bandwidth, ripple, parametric gain, and saturation power of a two-pump FOPA based on four-wave and six-wave models are studied and compared. Coupled-amplitude equations representing the non-degenerate FWM process in optical fiber are solved numerically to compute the parametric gain over the communication wavelengths. The behaviors of the performance parameters are critically analyzed and compared with different types of fluctuation strengths (or amplitudes) specified by the combinations of correlation length () and fluctuation amplitude (). Based on the results, it was found that the flat gain bandwidth for the four-wave model remains unchanged and is insensitive to the strengths of fluctuations. The gain ripples, however, get higher as the fluctuation strengths increase. On the other hand, the flat gain bandwidths of the six-wave model are hardly identified due to the tremendous and continuous ripples within the pump wavelengths. In addition, the minimum parametric gain values for both four-wave and six-wave models reduce as the fluctuation strengths increase. Also, the lowest value of parametric gain leads to the highest saturation power and vice versa. The dispersion fluctuations affect the FWM process's efficiency and deteriorate the overall amplifier performance, particularly for the six-wave model. The numerical analysis obtained via the six-wave model is especially useful since this model closely matches with practical circumstances.
基于四波混频（FWM）工作的光纤参量放大器（FOPA）是一种多功能器件，在光通信系统中的应用日益广泛。本文研究并比较了基于四波和六波模型的色散波动对双泵浦FOPA的带宽、纹波、参量增益和饱和功率性能的影响。通过数值求解表示光纤中非简并FWM过程的耦合振幅方程，计算通信波长范围内的参量增益。对性能参数的行为进行了严格分析，并与由相关长度（）和波动幅度（）组合指定的不同类型的波动强度（或幅度）进行了比较。基于这些结果发现，四波模型的平坦增益带宽保持不变，且对波动强度不敏感。然而，随着波动强度的增加，增益纹波会变得更高。另一方面，由于泵浦波长范围内存在巨大且连续的纹波，六波模型的平坦增益带宽几乎无法确定。此外，随着波动强度的增加，四波和六波模型的最小参量增益值都会降低。而且，参量增益的最低值会导致最高的饱和功率，反之亦然。色散波动会影响FWM过程的效率，并降低整个放大器的性能，特别是对于六波模型。通过六波模型获得的数值分析特别有用，因为该模型与实际情况密切匹配。
