Cascaded nonlinear-laser interactions in melilite-type crystals of Sr_2MgGe_2O_7 and Ba_2ZnGe_2O_7

摘要

The tetragonal germanates Sr_2MgGe_2O_7 and Ba_2ZnGe_2O_7 were found to be attractive, simultaneously χ ((2))- and χ ((2))-active nonlinear multifunctional crystals. Their basic optical properties were investigated and numerous nonlinearlaser effects, among them SRS, more than one-octave Stokes and anti-Stokes combs, SHG, THG, SFG, and efficient cascaded self-conversion (χ ((3))<->χ ((2)))-generation were observed in the visible and UV range. All recorded nonlinear-lasing components were identified and attributed to SRS-promoting vibration modes of the studied crystals.