Theoretical and experimental research on high-order stimulated Raman scattering in KGd(WO4)2

Eight wavelengths (465, 485, 508, 532, 559, 588, 621, and 658 nm) were synchronously generated by a single-pass potassium gadolinium tungstate (KGW) crystal Raman arrangement, which was pumped by a 532 nm, picosecond Nd: YAG laser with high peak power. To the best of our knowledge, this single-pass arrangement synchronously generated the highest-order Stokes and anti-Stokes among all known KGW Raman lasers. The first- to seventh-order Stokes conversion efficiency was calculated using Raman coupled equations. Further, the numerical results of third-order Stokes (621 nm) conversion efficiency were in good agreement with the experimental ones. We also analyze and discuss the factors because of which higher-order Stokes were not generated.