Stimulated Raman Scattering in Melilite‐Type Crystals Ca₂MgSi₂O₇ and Ca₂Ga₂SiO₇

Abstract

Abstractχ(3)‐nonlinear optical interactions in two melilite‐type stimulated Raman scattering (SRS)‐active non‐centrosymmetric crystals, Ca2MgSi2O7 and Ca2Ga2SiO7, formerly known as Nd3+‐laser media, are presented. Under picosecond pumping at 1.064 and 0.532 µm cascaded and cross‐cascaded effects occur in these tetragonal silicates. Besides the SRS‐promoting phonon modes with energy of ωSRS1 ≈ 908 cm−1 and ωSRS2 ≈ 668 cm−1 for Ca2MgSi2O7, and ωSRS1 ≈ 720 cm−1 and ωSRS2 ≈ 550 cm−1 for Ca2Ga2SiO7, respectively, combined phonon modes are observed. For Ca2MgSi2O7 new data in a broad wavelength range of refractive indices and their dispersion are given as well. The observed χ(3)‐nonlinear properties expand the functionality of the studied silicates and foreshadow their use in self‐frequency Raman laser converters (self‐SRS lasers).