钬铥双掺钨酸镱钾激光晶体光谱参数计算（英文）

Spectral Parameter Calculation of Ho^(3+),Tm^(3+) Co-doped KYb(WO_4)_2 Laser Crystal

采用顶部籽晶提拉法(TSSG)生长了钬铥双掺钨酸镱钾(KHo_(0.04)Tm_(0.06)Yb_(0.9)(WO_4)_2)激光晶体。测试了该晶体的吸收及荧光光谱,计算了其光谱参数。实验结果表明:该晶体在890~1 000 nm范围吸收带较宽,半峰宽为90 nm,计算了主峰1 000 nm处吸收截面为16.92×10^(-20)cm^2;Tm^(3+)在1 690~1 812 nm范围存在较宽的吸收带,半峰宽为118 nm,易于实现Yb→Ho、Yb→Tm、Tm→Ho的能量传递。根据Judd-Ofelt理论,计算了该晶体的光谱强度参数。根据Tm^(3+)、Ho^(3+)、Yb^(3+)离子能级图,讨论了产生1 750~2 200 nm荧光发射的3种能量传递方式。最后计算了主峰2 030 nm处受激发射截面为3.47×10^(-20)cm^2,表明该晶体可作为2μm波段优异的激光增益介质。

KHo0.04Tm0.06Yb0.9（WO4）2laser crystal was grown by the top seeded solution growth（TSSG）method.The absorption and fluorescent spectra of the crystal were measured,and the spectral parameters were calculated,too.The experimental results show that there is a broader absorption band at the range of 890-1 000 nm with a full width at half maximum（FWHM）of 90 nm.The absorption cross section of main emission peak at 1 000 nm is 16.92×10-20cm2.Meanwhile,Tm3＋ions in the crystal have a wider absorption band at 1 690-1 812 nm with a FWHM of 118 nm.Therefore,the energy transfer of Yb→Ho,Yb→Tm,Tm→Ho can be easily achieved.The spectral strength parameters of the crystal were calculated based on the Judd-Ofelt theory.According to the energy level diagram of Tm3＋,Ho3＋and Yb3＋ions,three kinds of energy transfer modes at 1 750-2 200 nm emission were discussed.The stimulated emission cross section of main emission peak at 2 030 nm is 3.47×10-20cm2,which indicates that the crystal can be used as an excellent laser gain medium at the range of 2μm.