Nonlinear LBO and BBO crystals for extreme light sources

Using the approach of heat filed symmetry change and rotation LBO crystals of more than 1.5 kg of weight were grown from MoO 3 -containing melt-solution. High quality optical elements up to 65 mm in diameter were produced. At the same time with this approach we obtained high quality BBO crystals about 400 g using NaBaBO 3 flux. Elements with apertures up to 30×30 mm 2 were produced. The progress in the dimensions of grown crystals provides the opportunity to use them in laser systems of multi petawatt and exawatt power level.