Study on Thermal Expansion of Nd3+: Gd3Ga5O12 Laser Crystal

Nd3+:Gd3Ga5O12(Nd:GGG) crystals were grown by the MF induction heating Czochraski technique. Samples of Φ 3 mm × 10 mm were cut from the boule along < 111 > and < 110 > direction, respectively. Their thermal expansions were measured with DIL402C thermal dilatometer. Results showed that the thermal expansion coefficient of Nd: GGG single crystal varied along with temperature. The higher the temperature, the bigger the thermal expansion coefficient. At the same temperature range, the thermal expansion ratio of different samples along the same direction was equal and that of different direction samples was little different. It was discovered that the thermal expansion ratio changed linearly in the range of 150 ∼ 1100 °C. Nonlinear variation appeared in the range of 25 ∼ 150°C.