We discuss in the present work the optimisation of the intensity distribution in transverse cross section of the pumpbeam of a Raman laser. In addition to the selection of optimum initial beam focusing and divergence, it allows increasingthe efficiency of frequency conversion in an optically pumped Raman laser. If the maximum on-axis intensity in the pumpbeam did not change, the largest effect for resonant stimulated Raman scattering is achieved in the beam with uniformamplitude distribution. The hypergaussian beam has a profile which is intermediate in shape between a Gaussian and uniformintensity distribution.
V. A. Batanov,
"Optimum pump beam profiling in a Raman laser", Proc. SPIE 2104, 18th International Conference on Infrared and Millimeter Waves, 210421 (30 August 1993); doi: 10.1117/12.2298505; https://doi.org/10.1117/12.2298505