Scattering defect in large diameter titanium-doped sapphire crystals grown by the Kyropoulos technique

The Kyropoulos technique allows growing large diameter Ti-doped sapphire for chirped pulse amplification (CPA) lasers. A scattering defect particular to Kyropoulos grown crystals is presented. This defect is characterized by different techniques: luminescence, absorption measurement, X-ray rocking curve, and transmission electron microscopy measurements. The impact of this defect on the potential application in CPA lasers is evaluated. The nature of this defect is discussed. Modified convexity of the interface is proposed to avoid the formation of this defect and increase the quality of the Ti-doped sapphire crystals.