Phase correlation in a Raman amplifier

Abstract

The effects of pump-beam temporal structure in a Raman amplifier were studied by using a frequency-doubled Nd:YAG laser. The experiment demonstrated that the Stokes wave becomes correlated with the pump as it is amplified. This leads to the result that, in general, the amplified Stokes wave is not coherent with the incident Stokes wave. The implications of this result for multiple-beam Raman amplifiers are discussed.