EFFECT OF LASER WAVELENGTH ON THE GENERATION EFFICIENCY OF STIMULATEDRAMAN EMISSION IN THE FEMTOSECOND REGIME

Rotational Raman lines are generated by stimulated Raman scattering an d four-wave Raman mixing using the fundamental (810 nm) and second har monic emission (405 nm) of a Ti:sapphire laser. The intensity of the R aman emission. measured at the different wavelengths, were compared an d confirmed to be more pronounced when a second harmonic emission is u sed as a pump beam. This is attributed to a larger Raman gain coeffici ent at shorter wavelengths and better beam quality obtained by the sec ond harmonic generation, as predicted from theory.