Raman beam combination in multiline operation

The effects of linear dispersion and four-wave mixing mechanisms on conversion efficiency and beam quality in Raman conversion of two-line XeF pump sources in H/sub 2/ are evaluated. Gain enhancement and gain cancellation occur as the lines propagate in and out of phase. An additional effect, that of phase compensation of the Stokes fields to the k-vector mismatch, has ben analyzed and shown to be a function of gain and degree of dispersion. Beam cleanup in parallel and crossed pump beam configurations is dependent on gain saturation, interaction distance relative to the Fresnel number and scale size of the pump aberration, and angle of injection