Growth and characterization of CsB3O5 crystals without scattering centers

CsB3O5 (CBO) single crystals without scattering centers have been successfully grown from the Cs2O-B2O3-MoO3 ternary system by the top-seeded solution growth method. The suitable region for CBO crystal growth was investigated by growth experiments, viscosity and volatility measurements, which confirmed that the optimal molar ratio of Cs2O : B2O3 : MoO3 was 2 : 3 : 2.5. By carefully controlling growth parameters, including the temperature gradient in the axis, rotation rate, cooling rate, and seed direction, a free of scattering centers CBO crystal with dimensions up to 29 6 31 6 47 mm(3) has been obtained. The grown CBO crystals possess high optical quality. The full-width at half-maximum (FWHM) of the rocking curve is 0.0057 degrees, and the optical homogeneity is at the level of 10(-6) cm(-1). The optical absorption at the critical wavelengths of 1064 and 532 nm was measured to be 200 and 60 ppm cm(-1), respectively. The laser-induced damage threshold (LIDT) at lambda = 1.064 nm and tau = 5.0 ns is about 4.50 GW cm(-2). Moreover, a high-power 278 nm ultraviolet (UV) laser through fourth harmonic generation (FOHG) of a diode-pumped 1112 nm Nd:YAG laser has been demonstrated in CBO crystal for the first time.