掺镱钼酸锶激光晶体的光谱研究

摘要

The spectra properties of Yb3+ ∶SrMoO4 crystal were investigated by employing the absorption and emission spectra. The strongest absorption is observed at 976 nm in the absorption spectra. The absorption cross-section is 1. 71 × 10-20cm2at 976 nm. The absorption band has a FWHM of 71 nm. The Stark energy levels of Yb3+ in Yb3+　∶ SrMoO4 crystal were obtained in the absorption spectra and low temperature emission spectra. The emission peak is at 1 021 nm. The emission band has a FWHM of 44 nm. The emission cross-section calculated by the reciprocity method is 1. 24X 10-20cm2 at 1 021 nm. The fluorescence lifetime of Yb3+ ∶ SrMoO4crystal is 878 μs by fitting the fluorescence decay curve. The laser parameters of Yb3+ ∶ SrMoO4 crystal were calculated by the spectral data, the pump saturation intensity parameter is 4. 35 kW/cm2, the minimum fraction of Yb3+ ions that must be excited to balance the ground state absorption and the gain exactly is 10. 08％, the minimum pump intensity is 0. 44 kW/cm2. For large absorption and emmision FWHM, long fluorescene lifetime and low laser threshold, Yb3+ ∶ SrMoO4crystal could be considered as a LD pumped laser gain material and used in femto-laser and tunable laser area.%通过晶体的吸收光谱和荧光光谱研究了Yb3+:SrMoO4激光晶体的光谱性能.由吸收光谱得到晶体在976 nm有最强吸收,该处的吸收截面为1.71×10-20cm2,吸收半峰宽为71 nm.由荧光光谱得到晶体的发射峰在1 021 nm,发射谱带半峰宽为44 nm.由倒易法计算了晶体的发射截面,计算得出晶体在1 021 nm处的发射截面为1.24×10-20cm2.通过拟合荧光寿命衰减曲线得到Yb3+:SrMoO4晶体的荧光寿命为878μs.由光谱数据计算了Yb3+:SrMoO4晶体的激光参数,计算得到饱和泵浦功率密度为4.35 kW/cm2,在激光输出波长处净透过所需要激发粒子的最小分数为10.08%,最小泵浦功率密度为O.44 kW/cm2.Yb3+:SrMoO4晶体具有较大的吸收和发射半峰宽,较长的荧光寿命和较低的激光阈值,可成为一种潜在的LD泵浦激光材料,可能应用于飞秒激光及可调谐激光领域.