Growth and optical properties of Pr-Mg co-doped LiNbO3 crystal using Bridgman method

Praseodymium ion (0.5, 1 mol%) and magnesium ion (1, 5 and 7 mol%) co-doped LiNbO3 crystals have been grown by Bridgman method. The crystal was designed to absorb idler generated by the quasi parametric chirped pulse amplification (QPCPA) system near 1588 nm (the pump is 1064 nm and signal is 3200 nm). The contents of Praseodymium (Pr) and magnesium (Mg) ions in the crystals were measured, and the crystal structure and Raman vibration mode were characterized. The optical properties of the crystal were systematically investigated, the transmittance of the crystal at 3200 nm and 1064 nm was about 75%, and there is an obvious absorption band at 1588 nm. The thermal properties of the crystal were studied, and the results showed that the thermal properties of the crystal were improved by doping Mg2+. The laser damage threshold of Pr3+(0.5mol%)-Mg2+(7mol%) co-doped LiNbO3 crystal was as high as 109.73 × 107 W/cm2 (@1064 nm, 5 ns).