Zeng Fan-ming, Zhang Ying, Sun Jing, Liu Jing-he
College of Material Science and Engineering of Changchun University of Science and Technology, Changchun 130022, China.
Guang Pu Xue Yu Guang Pu Fen Xi. 2009 May;29(5):1323-6.
Neodymium-doped gadolinium gallium garnet (Nd:GGG)crystal is the best operation material of solid-state heat-capacity laser. In the present paper, Nd:GGG single crystal was grown by Czochralski (Cz) method. Fluorescence spectra and absorption spectra were measured. At the same time, the spectral parameters of Nd:GGG laser crystal were calculated by Judd-Ofelt theory, including absorption and emission cross-section, intensity parameters, radiative transition probability, fluorescence branch ratio and fluorescent lifetime. According to the measurement and calculation of absorption spectra, it is illustrated that the main absorption peak of Nd: GGG crystal was at near 808 nm, the absorption cross section of the main peak at 808 nm sigma abs, was equal to 4. 35 x 10(-20) cm2. The FWHM of absorption line-width was equal to 8 nm, and the absorption intensity became stronger with the increase in Nd3+ ions concentration. According to the measurement and calculation of fluorescence spectra, the fluorescence emission peak was at near 1062 nm, which corresponds to 4F(3/2) - 4(I(11/2) emission band of Nd3+ ions. The radiative transition probabilityof the main emission peak at 1062 nm A(jj') was equal to 1 832.01 s(-1). The fluorescence branch ratio betajj was equal to 45.07%. The fluorescence lifetime r was equal to 250 micros. The stimulated emission cross section sigma(lamda) was equal to 21.58 x 10(-20) cm2. The laser operationof 4F(3/2) - 4I(11/2) transition can be realized due to the larger fluorescence branch ratio and stimulated emission cross section
掺钕钆镓石榴石（Nd:GGG）晶体是固态热容激光器的最佳工作材料。本文采用提拉法生长了Nd:GGG单晶。测量了其荧光光谱和吸收光谱。同时，利用Judd-Ofelt理论计算了Nd:GGG激光晶体的光谱参数，包括吸收和发射截面、强度参数、辐射跃迁概率、荧光分支比和荧光寿命。根据吸收光谱的测量和计算结果表明，Nd:GGG晶体的主要吸收峰在808nm附近，808nm主峰的吸收截面σabs为4.35×10⁻²⁰cm²。吸收线宽的半高宽为8nm，且随着Nd³⁺离子浓度的增加吸收强度增强。根据荧光光谱的测量和计算结果，荧光发射峰在1062nm附近，对应于Nd³⁺离子的4F(3/2) - 4I(11/2)发射带。1062nm主峰的辐射跃迁概率A(jj')为1832.01s⁻¹。荧光分支比βjj为45.07%。荧光寿命τ为250μs。受激发射截面σ(λ)为21.58×10⁻²⁰cm²。由于较大的荧光分支比和受激发射截面，可实现4F(3/2) - 4I(11/2)跃迁的激光运转
