【作者】 许银生；

【导师】 陈国荣； Adam Jean-Luc；

【作者基本信息】 华东理工大学 ， 材料科学与工程， 2011， 博士

【摘要】 本文第一部分主要研究了元素铟对硫卤玻璃的形成、三阶非线性光学性能和稀土离子掺杂发光的影响。铟和镓属同族元素,但原子量较大,因此形成玻璃的声子能量更低、折射率更大,宏观上各种相应的性能也应有所提高,其主要研究结果如下：GeSe2-In2Se3-CsI准三元系统具有相当大的玻璃形成区。随着CsI含量的增加,短波截止边发生蓝移,玻璃的颜色由黑色逐渐向深红色,直至橙色过渡。玻璃的透过范围介于0.56-16μm之间。拉曼光谱表明,玻璃网络中主要存在[GeSe4]和[InSe4.xIx]结构单元。通过光克尔技术测试,得到71.25GeSe2-23.75In2Se3-5CsI玻璃中的χ(3)和n2分别为10.07×10-12esu和6.5×10-14 cm2/W,是As2S3玻璃的2倍多。分析其结构与χ(3)的关系,发现[GeSe4]和[InSe4]四面体结构单元浓度的增加有利于提高χ(3)值。首次在Tm3+离子掺杂的GeS2-In2S3-CsI玻璃中发现了位于700 nm的上转换红色发光,并且通过稀土离子共掺,也可以实现从红色到绿色波段之间的调整,有望用于特殊波长的固态激光或可调谐光源。随着基质中掺杂的Tm浓度增加,红色发光逐渐增强,在1mol%Tm2S3时,发光最强。通过吸收光子数测定,表明在808 nm泵浦时该发光是双光子吸收过程。结果表明：通过Er3+离子共掺、提高Tm3+离子和铟的含量都有利于700 nm的红色上转换发射。在808nm激发下,通过调整基质与稀土离子浓度,得到从1.35到1.7μm的半高宽大于160nm的超宽带近红外发射。最优化的组成为0.1mol% Er2S3和0.5mol% Tm2S3共掺杂的70GeS2-20In2S3-10CsI玻璃。发射光谱和荧光衰减曲线表明稀土离子共掺有利于形成混合键,从而抑制相同稀土离子之间的交叉弛豫,降低能级间的无辐射跃迁。第二部分主要研究了Pr3+/yb3+离子对在氧氟玻璃及微晶玻璃中下转换能量转移近红外发射。通过熔融淬冷法制备了Pr3+/Yb3+离子共掺的40SiO2-30Al2O3-18Na2O-12LaF3氧氟玻璃,得到近红外发射效率最高为6%。比较基玻璃与微晶玻璃的吸收光谱和发射光谱发现在微晶化过程中,由于玻璃中形成PrF3与LaF3晶体类型一致,因此Pr3+离子优先进入晶体并使其自身发射增强,导致在该氧氟玻璃中能量转移效率不能通过微晶化过程来提高。近红外发射的提高主要是由于Yb3+离子进入晶体后无辐射跃迁被抑制及微晶化后泵浦效率的提高。更多还原

【Abstract】 The first part of the thesis mainly emphasized on the glass formation, third-order nonlinearity, and emission properties of the Indium-based chalcohalide glasses. For the presence of relatively heavy atoms (In), these glasses have the lower maximum phonon energy and higher refractive index. Thus higher radiative emission rates and larger nonlinearity could be yielded. The main results are shown as follows.A fairly large glass-forming domain of the GeSe2-In2Se3-CsI glasses is determined. These glasses show excellent transparency from 0.6 to 16μm. With the addition of CsI, the Tg decreases, the visible absorption edge shifts toward the short wavelength region. Correspondingly, the color of the samples varies from black through red to orange following the increased content of CsI. Raman spectra show that [GeSe4] and [InSe4.xIx] tetrahedral are the major structural units in the glass network. The obtainedχ(3) and n2 of 70GeSe2-20In2Se3-10CsI glass are as large as 10.07×10-12esu and 6.5×10-18m2/W, respectively, more than twice that of As2S3 glass. We have shown that the n2 variation may be related to the total number of [GeSe4] and [InSe4] tetrahedral units.Bright red emission in the Tm3+ ions doped GeS2-In2S3-CsI chalcohalide glasses pumped by an 808 nm near IR high power laser diode was observed for the first time. By codoping different concentration of Er3+ ions, emission can be tuned from monochromatic red to green, which is significant for their applications such as light emitting displays, lasers, and optoelectronic devices. The analysis demonstrates that the intensive red and green luminescence is generated from two-photon absorption process. The Er3+ ions codoping, higher concentrations of Tm+ ions and/or indium favor the 700nm red emission.Broadband emission extending from 1.35 to 1.7μm with the full width at half-maximum (FWHM) of-160 nm was obtained at room temperature in a 0.1 mol% Er2S3 and 0.5 mol% Tm2S3 co-doped 70GeS2-20In2S3-10CsI glass sample under 808 nm excitation. The emission spectra and fluorescence decay curves indicate that the Tm3+-Er3+ ions co-doping suppressed the cross relaxation between Tm-Tm or Er-Er ions due to formation of mixed bonds and therefore a decrease of non-radiation transition probability among each rare earth’s energy levels.The second part works on the downconversion emission in the Pr3+/Yb3+ ions codoped oxyfluoride glasses. Near-IR downcoversion emission with the 6% quantum yield has been realized in the Pr3+/Yb3+ ions codoped 40SiO2-30Al2O3-18Na2O-12LaF3 glass. Comparing the absorption and emission spectra of the glasses with that of the glass ceramics, the Pr3+ ions have the priority to enter the LaF3 crystals due to the similar crystal lattice, thus the energy transfer efficiency decreased in the present glass by crystallization. The enhancement of the near IR emission is due to the suppressed non-radiative transition and the enhancement of the pumping efficiency.更多还原