Homogeneity characterization in AgGaGeS4, a single crystal for nonlinear mid-IR laser applications

Jérémy Rame (1) , Johan Petit (1) , Denis Boivin (1) , Nicolas Horezan (1) , Jean Michel Melkonian (2) , Antoine Godard (2) , Bruno Viana (3)

1 DMAS, ONERA, Université Paris Saclay [Châtillon]
2 DPHY, ONERA, Université Paris Saclay [Palaiseau]
3 IRCP - Institut de Recherche de Chimie Paris

Single crystal quality is a key issue for optical applications. Indeed, in optical frequency conversion processes, defects in single crystals can drastically decrease the conversion yield. The study of the quality of an AgGaGeS4 single crystal is presented in this work. Scanning Electron Microscopy (SEM) combined with Energy Dispersive X-Ray Spectroscopy (EDS) was used to perform a chemical analysis mapping of a large size single crystal cut (surface 26 x 20 mm 2). Chemical inhomogeneity was found along the crystal growth axes and confirmed by optical characterization showing laser beam perturbations. Compounds volatility, lack of melt homogenization and instability of crystallization front might explain this chemical inhomogeneity. Solutions to improve the crystal growth process and enhance the crystal's quality are finally proposed.

Mots clés: VOLUME DEFECTS; BRIDGMAN TECHNIQUE; SULFIDES; NONLINEAR OPTIC MATERIALS; MEB; MONOCRISTAL; DEFAUT

Mots clés: MONOCRISTAL; DEFAUTS; MEB

Domaines: Sciences de l'ingénieur [physics]; Physique [physics]; Chimie

Jérémy Rame, Johan Petit, Denis Boivin, Nicolas Horezan, Jean Michel Melkonian, et al.. Homogeneity characterization in AgGaGeS4, a single crystal for nonlinear mid-IR laser applications. Journal of Crystal Growth, 2020, 548 (125814), pp.1-7. ⟨10.1016/j.jcrysgro.2020.125814⟩. ⟨hal-02966569⟩