新型激光自倍频Yb:YAB晶体的性质研究

Some Properties of New Self-Frequency-Doubling Crystal Yb_xY_(1-x)Al_3(BO_3)_4

采用助熔剂法生长了不同配比的激光自倍频晶体Yb:YAl3(BO3)4(Yb:YAB).测量了晶体的室温吸收谱和荧光光谱,室温下仅存在一个吸收带,主吸收峰在976nm处,能与InGaAsLD有效耦合.在1.03μm处存在一个强荧光峰.测定了晶体的热膨胀系数,在平行与c轴方向的热膨胀系数较大,α2=9.4×10-6/K,约为a轴方向的3.5倍.在10％的Yb:YAB晶体中,以入射功率为11W,波长为977nm的光纤耦合二极管激光器泵浦得到4.3W的基频光波输出,斜效率为48％;在同样实验条件下得到了1.1w的自倍频绿光输出,总转换效率为10％.

Single crystals of different ytterbium-doped yttrium alumium tetraborate (Yb:YAl3 (BO3)(4),Yb:YAB) were grown by the flux method. The absorption and fluorescence spectra of Yb3+:YAl3(BO3)(4) crystals were measured. In the absorption spectra, there is only one absorption band at 976nm, which is suitable for InGaAs diode laser pumping. In the fluorescence spectra, there is one fluorescence peak at 1.03mum. The thermal expansion presents strong anisotropic character, and the thermal expansion of c-direction is about 3.5 times than that of a-direction. The relationship between thermal properties and crystal structure was discussed. 4.3W output power. at 1040nm can be obtained when pumped by 11W fibre-coupled laser diode at 977nm, and the slope efficiency is 48%; At the same experiment condition, 1.1W cw green output can be achieved, with a diode-to-green optical conversion efficiency of 10%.