Synthesis and growth of AgGaGeS4, a promising material for the laser frequency conversion in the mid-IR range

AgGaGeS4 (AGGS) is a promising nonlinear crystal for mid-IR laser applications. This paper presents the processing steps of this material, the synthesis of polycrystals and the crystal growth using the Bridgman-Stockbarger technique. It also presents the solutions to obtain high quality single crystals taking into account the decomposition at high temperature of the AGGS phase due to the high volatility of GeS2. AGGS crystals with 28 mm diameter and 70 mm length were grown. These crystals have a good homogeneity and high transparency in the 0.5-11.5 µm spectral range making its suitable for optical experiments.