Dependence of broadband Raman amplification in dispersive media on the pump–Stokes input correlation

Abstract

A statistical theory is presented of the dependence of Raman amplification in a dispersive medium on the cross correlation of the pump and the Stokes input. Both forward and backward amplification of broadband Stokes radiation by a broadband pump are considered. It is shown that group-velocity dispersion reduces the gain enhancement that is observed when the pump and the Stokes input are correlated. The curve for the gain enhancement versus the relative time delay (advance) of the two waves becomes asymmetric and broader than it would in the absence of dispersion. For typical parameters the lack of perfect correlation between the Stokes output from a Raman generator and the pump reduces the gain enhancement in a cascaded Raman amplifier by only a few percent.