Tm^3＋掺杂的MFT玻璃上转换发光及光学增益

报道了一种新型ＭＦＴ（Ｍｕｌｔｉ－Ｆｌｕｏｒｉｄｅ－Ｔｅｌｌｕｒｉｄｅ）玻璃材料（组份为５０ＴｅＯ２－１９．７ＰｂＦ２－１０ＡｌＦ３－１０ＢａＦ－０．３Ｔｍ２Ｏ３）的制备方法,测量了６５０ｎｍ激发下Ｔｍ＾３＋离子掺杂在ＭＦＴ玻璃材料中源于＾１Ｄ２→＾３Ｈ６（４７６ｎｍ）跃迁的两组蓝色上转换发光研究了上转换发光强度随激光率的变化关系,并且首次应用ＡＳＥ（Ａｍｐｌｉｆｉｅｄ Ｓｐｏｎｔａｎｅｏｕｓ Ｅ     

方波激发下Er3+上转换绿光发光动力学过程的研究

用方波电源驱动808 nm,980 nm激光二极管(LD)激发Er3+掺杂的亚碲酸盐氟氧化物玻璃,测量2H11/2,4S3/2能级上转换发光的上升和衰减,不同波长激发下的上升时间常数不同,说明808 nm LD和980 nm LD激发下2H11/2,4S3/2能级上转换激发途径不同.通过建立速率方程模型分析了4S3/2能级的上升特性与中间能级寿命的关系,从而确定了两种波长激发下上转换绿光的激发机理.     

铕激活银离子导电玻璃的白光发射

空气气氛下在铕激活银离子导电玻璃中,实现了Eu³⁺→Eu²⁺的还原。通过改变基质中Ag₂O的含量,能够调整Eu³⁺/Eu²⁺比率,从而实现白光发射。在Ag₂O的摩尔分数为30%时,发射光的色坐标为(x=0.31,y=0.36),色温为5 000 K。对Ag₂O的引入引起Eu³⁺→Eu²⁺还原的机理进行了分析。可以相信铕激活银离子导电玻璃将成为白光LED理想的基质材料。     

硼碲酸盐玻璃材料中Er3+光谱性质对组分的依赖关系

采用熔融淬火技术制备了一组Er3+掺杂的变组分硼碲酸盐玻璃材料.测量了玻璃的折射率、吸收光谱及4I13/2→4I15/2跃迁的荧光寿命.利用标准的三参量Judd Ofelt理论对Er3+的光学跃迁性质进行了计算,并对Er3+离子的4I13/2能级的量子效率进行了研究.结果发现,随着样品中TeO2含量的增加样品的折射率变大,三个Judd Ofelt参量中Ω2随着样品组分的改变较明显,而另外两个参量Ω4和Ω6的变化较小.还发现随着TeO2含量的增加4I13/2→4I15/2辐射跃迁几率增大,并且该跃迁的量子效率增加.这一研究结果表明,在硼酸盐玻璃材料中引入TeO2可以有效地改善其中稀土离子的量子效率和辐射跃迁性能.     

SrAl12O19∶Pr3+中的热激发

研究了SrAl12O19∶Pr3+的光谱中3P1 和1I6的发射. 用3P1→3H5与3P0→3H5发射强度之比测量了温度，通过1I6→1G4与3P0→1G4发射强度之比，讨论了热激发对3P0可见光发射效率的影响. 关键词： 热激发 温度测量 三价镨离子     

用光子级联发射测量SrAl12O19中Pr3+3P0能级的量子效率

在SrAl12O19中，Pr^3 的^1S0处于4f5d之下，可以观察到光子级联发射。研究了SrAl12O19:Pr^3 的光谱性质。把第一步发射的谱线强度作为第二步发射起始能级上电子数的度量，测量了SrAl12O19:Pr,Mg中Pr^3 3P0能级的量子效率，测量结果反映了浓度猝灭的影响。低浓度样品中可见区发射的量子效率约为70％，它显著小于1的原因可能是^1I6的热激发。     

The effects of Er3+ ion concentration on 2.0-μm emission performance in Ho3+/Tm3+ co-doped Na5Y9F32 single crystal under 800-nm excitation

Na₅Y₉F₃₂ single crystals doped with ~0.8-mol% Ho³⁺,~1-mol% Tm³⁺,and various Er³⁺ ion concentrations were prepared by a modified Bridgman method.The effects of Er³⁺ion concentration on 2.0-μm emission excited by an800-nm laser diode were investigated with the help of their spectroscopic properties.The intensity of 2.0-μm emission reached to maximum when the Er³⁺ ion concentration was ~1 mol%.The energy transfer mechanisms between Er³⁺,Ho³⁺,and Tm³⁺ ions were identified from the change of the absorption spectra,the emission spectra,and the measured decay curves.The maximum 2.0-μm emission cross section of the Er³⁺/Ho³⁺/Tm³⁺tri-doped Na₅Y₉F₃₂ single crystal reached 5.26 × 10^-21 cm².The gain cross section spectra were calculated according to the absorption and emission cross section spectra.The cross section for ~2.0-μm emission became a positive gain once the inversion level of population was reached 30%.The energy transfer efficiency was further increased by 11.81% through the incorporation of Er³⁺ ion into Ho³⁺/Tm³⁺ system estimated from the measured lifetimes of Ho³⁺/Tm³⁺-and Er³⁺/Ho³⁺/Tm³⁺-doped Na₅Y₉F₃₂single crystals.The present results illustrated that the Er³⁺/Ho³⁺/Tm³⁺tri-doped Na₅Y₉F₃₂ single crystals can be used as promising candidate for 2.0-μm laser.     

Trapezoidal pulse shaping for pile-up pulse identification in X-ray spectrometry

Energy resolution is affected by the intrinsic energy resolution of the detector, ballistic deficit, pile-up pulses and noise. Pile-up pulses become the dominant factor that degrades energy resolution after the system is established, so pile-up rejection is often applied to obtain good energy resolution by discarding pulses that are expected to be contaminated by pile-up. However, pile-up rejection can reduce count rates and thus lower the measurement precision. In order to improve count rates and maintain energy resolution, a new method of pile-up pulse identification based on trapezoidal pulse shaping is presented. Combined with pulse width discrimination, this method is implemented by recording pulses that are not seriously piled up. Some experimental tests with a Cu-Pb alloy sample are carried out to verify the performance of this method in X-ray spectrometry. The results show that the method can significantly improve count rates without degrading energy resolution.     

稀土铝磷酸盐玻璃中镨离子的可见光致发光

研究了稀土铝磷酸盐5.8Li2O-3CaO-5BaO-6Al2O3-4.2La2O3-66P2O5(LCBALP)玻璃中镨离子的可见光致发光特性,采用积分球测试系统对其绝对荧光光谱进行表征。1D2→3H4的自发辐射跃迁几率和最大受激发射截面分别为926.5 s-1和3.5×10-21cm2。在蓝色LED激发下,镨离子可见特征发射峰的辐射通量和光通量分别为112.6μW和29.7 mlm,其可见特征发射的总荧光量子产率为4.1%。光学玻璃中镨离子的光谱评估为其在光电子器件和紧凑型照明光源领域的发展提供了重要的参考依据。     

新型掺铒钆硼硅酸盐玻璃的制备和光学性质的研究

用高温熔融法制备了成分为Gd2O3,SiO2,B2O3和Na2O的新型玻璃体系,探索了该玻璃体系的成玻范围,发现该系统在B2O3:20%以上,SiO2:0～50%,Gd2O3:0～30%的范围内均可形成完全透明的玻璃.在Gd2O3:30%,B2O3:60%和SiO2:60%,B2O3:30%两个组分附近时玻璃轻微失透.除此以外,在其他组分实验上没有得到玻璃.根据差热分析的数据,计算得到的玻璃析晶倾向参数β在0.32～1.76之间,说明含10%Gd2O3的钆硼硅酸盐玻璃具有较强的形成能力;利用McCumber理论计算出样品的吸收和受激发射截面,并从玻璃1.5 μm的吸收光谱出发拟合出了J-O参数,进而计算了Er3 离子各相关能级的理论振子强度、实验振子强度和自发辐射速率等参数.同时,用Er3 离子1.5 μm发射光谱的半高全宽与其峰值发射截面的乘积值对含10%Gd2O3钆硼硅酸盐玻璃1.5μm发射的增益带宽作出了表征,结果表明,含10%Gd2O3玻璃体系的FWHM×σepeak值均大于已有报道的硅酸盐、磷酸盐和锗酸盐玻璃,其中最大值和氧氟硅酸盐玻璃的相差不多.