镁对掺铒铌酸锂晶体光谱性质的影响.pdf

摘要铌酸锂晶体凭借其优良的物理特性,成为制备光波导最常用的晶体材料。它的很多物理特性与其本身组分和晶体缺陷密切相关。。,所以弄清重掺镁对掺铒铌酸锂晶体的影响及其作用机制十分必要。本文在此方面获得一些结论,为进一步完善掺Er铌酸锂波导放大器和激光器性能奠定了一定基础。本文工作主要包含以下三个方面: 1,在室温下分别测量了掺MgO浓度为2,4,6,8 m01%的Y切 Er(1m01%):LiNb03晶体非偏振吸收谱,观察到掺镁铌酸锂晶体光学吸收边都有明显蓝移,随着掺镁浓度增加,吸收带吸收系数积分值减小。这表明掺镁对各能级的吸收有抑制作用。,得到不同掺镁浓度E,电子跃迁强度的实验值和理论值。 2,在800 nm光泵浦时,对波长为550nm绿荧光发射能级离子衰减进行探测,发现了衰减曲线的非指数现象和阈值效应,并研究出非指数现象是由Er离子簇数量增加导致非辐射跃迁交叉弛豫现象的发生引起的。正是因为这种交叉弛豫的发生,使中间能级离子数增加,导致了对绿色荧光发射的抑制和对1540 nm 荧光发射的加强。 3,从微观缺陷结构上分析了掺镁对铌酸锂晶体影响。对比分析了已有掺镁模型,并且对其进行了部分完善。根据完善后掺镁模型和前面的实验结果,推断出Er离子簇数量与晶体中Li空位缺陷相关一重掺镁使晶体中Li空位数量减少,致使Er离子簇数量增加,非辐射跃迁交叉弛豫增加,衰减曲线的非指数性增强,衰减寿命减少。同时,针对上述结论,提出两个验证实验设计。关键词:铌酸锂晶体J-O理论吸收光谱光谱参数铌酸锂缺陷模型 ABSTRACT Lithium niobate miNb03)has e mon crystal material tofabricate waveguide important properties stronglydepend on position and latticedefects insidetheLithium niobate MgO doped Er:LiNb03 can enhance emission and suppress green upconversion thewaveguide amplifier andlaser monly concerned andstudied,it isgreatlynecessary tostudy theeffectsandmechanism ofactionabout deep Mg—doping to Er: experimental results are reached inthis can offerconsiderable guidance tofurtherwork inthe future. The main work ofthe dissertation can besummarized asfollowing threeaspects: temperature Y cutEr(1m01%):LiNb03 unpolarized absorption spectrum with several MgO-codoped concentration(2,4,6,8m01%)were measured,and an obvious blueshiftofMg doped LiNb03 opticalabsorption edge the growth ofMg concentration,integral quantities ofabsorption coefficient in absorption band decrease which shows Mg doping restrainstheabsorption ofeach energy unpolarized absorption spectrum was analyzed with J—Otheory, Experimenml andtheoreticalvalue ofEr3+electronics transitionintension isobtained atdifferentMg concentration dope