Crystal growth and characterization of 4 in. YCa4O(BO3)3 crystal

• 4 in. YCOB crystals without inclusions and cleavage were grown.
• The conversion ratio should keep below 50% to avoid inclusions.
• Small perpendicular temperature gradient were applied to avoid cleavages.
• YCOB showed high optical homogeneity and high laser-induced damage threshold.
• Non-collinear OPCPA experiment near 800 nm were demonstrated successfully.

YCa4O(BO3)3 (YCOB) is an important nonlinear optical crystal with good thermal, mechanical and nonlinear optical properties. However, growth of YCOB with large size and high quality was seldom reported. In this work, 4 in. YCOB crystals without inclusions and cleavages were grown successfully. These YCOB crystals exhibit excellent nonlinear optical properties, and have been used in high-energy and high-power ultra-short laser systems successfully.