Ho^(3+):LiYF_4晶体的中红外发光特性  

Mid-infrared Emission Properties of Ho^(3+) Doped LiYF_4 Single Crystals

作　　者：彭江涛[1] 夏海平[1] 汪沛渊[1] 胡皓阳[1] 唐磊[1] 

机构地区：[1]宁波大学光电子功能材料重点实验室,浙江宁波315211

出　　处：《发光学报》2013年第6期702-710,共9页Chinese Journal of Luminescence

基　　金：国家自然科学基金(51272109;50972061;61275180);浙江省自然科学基金(R4100364;Z4110072);宁波市自然科学基金(2012A610115);宁波大学王宽诚幸福基金资助项目

摘　　要：用坩埚下降法制备了Ho3+离子掺杂的LiYF4单晶。测定了Ho3+:LiYF4晶体的偏振吸收光谱。应用Judd-Ofelt理论分别计算了Ho3+:LiYF4晶体中Ho3+离子的有效强度参数Ω2,4,6、能级跃迁振子强度fexp和fcal、自发辐射跃迁几率A、荧光分支比β、辐射寿命τrad等光谱参数。测定了样品在640 nm光激发下的红外发射光谱,观测到由Ho3+离子的5I6→5I7跃迁所致的2.8～3μm中红外发光,以及在1.2μm(5I6→5I8)和2.0μm(5I7→5I8)处较强的荧光。Ho3+:LiYF4单晶样品的吸收峰线宽较宽,计算得到1.2μm和2.0μm的峰值发射截面分别达到0.20×10-20cm2和0.51×10-20cm2,同时测定了1 191 nm(5I6→5I8)和2 059 nm(5I7→5I8)发射的荧光寿命。研究结果表明:Ho3+:LiYF4晶体在2.0～3μm波段的中红外激光器中有较大的应用前景。The Ho3＋ -doped LiYF4 single crystals were grown by Bridgman method. The axial and transverse absorption spectra of Ho3 ＋ ions in LiYF4 crystals were measured. The Judd-Ofeh theory was applied to calculate the J-O effective intensity parameters Ω2,4,6, spontaneous radiative transition rate, branching ratio, radiative lifetime of or transition and π transition. IR emission spectra of Ho3 ＋ ： LiYF4 single crystals were measured under 640 nm wavelength excitation, and the emission band around 2.9, 1.2 and 2.0 μm due to 5Ⅰ6→5Ⅰ7,5Ⅰ6→5Ⅰ8,5Ⅰ7→5Ⅰ8 transition were observed. Based on the absorption spectra, the maximum calculated emission cross section emission at 1.2 and 2.05 μm in LiYF4： Ho3 ＋ crystal are 0.20 x 10 -20 and 0.51 x 10 -20 cm2, respectively. In the meantime, the emission lifetimes at 1 191 nm （5Ⅰ6→5Ⅰ8） and 2 059 nm （517→5Ⅰ8） were determined to be 2.13 and 17.23 ms. The research results indicate that Ho3 ＋ ： LiYF4 crystal is a good candidate for mid- infrared laser media.

关 键 词：偏振吸收光谱 LiYF4 Ho3+晶体 中红外荧光 Jodd-Ofelt理论 

分 类 号：TN248.1[电子电信—物理电子学]