Abstract：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 σabs was equal to 4.35×10-20 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 1 062 nm, which corresponds to 4F3/2-4I11/2 emission band of Nd3+ ions. The radiative transition probabilityof the main emission peak at 1 062 nm AJJ′ was equal to 1 832.01 s-1. The fluorescence branch ratio βJJ was equal to 45.07％. The fluorescence lifetime τ was equal to 250 μs. The stimulated emission cross section σ(λ) was equal to 21.58×10-20 cm2. The laser operation of 4F3/2-4I11/2 transition can be realized due to the larger fluorescence branch ratio and stimulated emission cross section.
Key words：Nd∶GGG laser crystal;Absorption spectra;Fluorescence spectra;Calculation of spectral parameters
[1] REN Guo-guang, HUANG Yu-nian(任国光, 黄裕年). Laser and Infrared(激光与红外)，2002, 32(4): 211. [2] Fedin A V, Basiev T T, Rulev A V, et al. SPIE, 2002, 4644: 293. [3] Baburin N V, Galagan B E, Yu K Danikeiko, et al. Quantum Electronics, 2001, 31(4): 303. [4] Bruno Labranche, Wu Qun，Galarneau Pierre. SPIE, 1998, 2041: 326. [5] Maeda K, Wada N, Umino M, et al. Jap. J. Appl. Phys., 1984, 23(10): 759. [6] YANG Wen-qin, WU Mei-qin, CHEN Jin-kai, et al(杨文琴, 吴梅琴, 陈金铠, 等). Spectroscopy and Spectral Analysis(光谱学与光谱分析), 2001, 21(1): 28. [7] Bhatt R, Kar S, Bartwall K S, et al. Solid State Communications, 2003, 127: 457. [8] ZHANG Qing-li，YIN Shao-tang，WANG Ai-hua(张庆礼，殷绍唐，王爱华). Journal of Quantum and Electronics(量子电子学报)，2002，19(6):481. [9] WANG Guo-fu(王国富). J. Synth. Cryst.(人工晶体学报), 1998, 27(4): 390. [10] FENG Yan, CHEN Xiao-bo, LI Kun, et al (冯 衍, 陈晓波，李 昆，等). Spectroscopy and Spectral Analysis(光谱学与光谱分析), 1998, 18(4): 390. [11] Jorgensen C K，Reisfeld R，et al. J. Less Common Metals，1983，93: 107. [12] Ke szei B, Paite J, Vandlik J, et al. J. Cryst. Growth, 2001, 226(1): 95. [13] SUN Jing，LIU Jing-he, et al(孙 晶, 刘景和, 等). Journal of the Chinese Ceramic Society(硅酸盐学报)，2004，32(5): 585. [14] YANG Jian-hu, DAI Shi-xun, DAI Neng-li，et al(杨建虎, 戴世勋, 戴能利, 等). Spectroscopy and Spectral Analysis(光谱学与光谱分析), 2003, 23(6): 1065. [15] ZHANG Qing-li, HE Wei, SUN Dun-lu, et al(张庆礼, 何 伟, 孙敦陆, 等). Spectroscopy and Spectral Analysis(光谱学与光谱分析), 2005, 25(3): 329.
