Correlation between geometric parametric instability sidebands in graded-index multimode fibers

The spectral analysis of the light propagating in normally dispersive graded-index multimode fibers is performed under initial noisy conditions. Based on the obtained spectra with multiple simulations in the presence of noise, we investigate the correlation in energy between the well-separated spectral sidebands through both the scattergrams and the frequency-dependent energy correlation map and find that conjugate couples are highly correlated while cross-combinations exhibit a very poor degree of correlation. These results reveal that the geometric parametric instability processes associated with each sideband pair occur independently from each other, which can provide significant insights into the fundamental dynamical effect of the geometric parametric instability and facilitate the future implementation of high-efficiency photon pair sources with reduced Raman decorrelations.

Automated summary

This study focuses on the spectral analysis of light propagating in normally dispersive graded-index multimode fibers under initial noisy conditions. The research reveals high correlation between conjugate couples of well-separated spectral sidebands, while cross-combinations exhibit a poor degree of correlation. These results provide insights into the independent occurrence of geometric parametric instability processes associated with each sideband pair, which can be beneficial for the future implementation of high-efficiency photon pair sources with reduced Raman decorrelations.