Tm3+/Ho3+/Yb3+掺杂Ga2O3-GeO2-Li2O玻璃的上转换发光性能研究

采用熔融淬冷法制备了Tm^3＋/Ho^3＋/Yb^3＋掺杂的Ga2O3-GeO2-Li2O玻璃。测试了样品的拉曼光谱、吸收光谱、980 nm和808 nm泵浦下的上转换发射光谱。详细调查了在980 nm和808 nm激发下不同的Yb2O3掺杂含量对Tm^3＋/Ho^3＋掺杂的镓锗锂玻璃的上转换发射光谱的影响,分析了稀土离子间的能量传递。研究发现：980 nm泵浦下样品观察到明显的545 nm和657 nm发射和微弱的476 nm发射峰。随着Yb^3＋浓度的增大,由于Yb^3＋对Tm^3＋和Ho^3＋的有效的能量传递增强了红光和绿光发射强度,红光的增长率是快于绿光的,Yb2O3的掺杂量为0.7 mol%时I657/I545强度比率达到最高。808 nm激发下可以观察到弱的476 nm的蓝光和545 nm的绿光及强烈693 nm发射。

Effect of alkali metal oxides R_2O (R=Na,K) on 1.53 μm luminescence of Er^(3+)-doped Ga_2O_3-GeO_2 glasses for optical amplification

This paper reported the thermal stability and spectroscopic properties of Ga2O3-GeO2-Na2O-K2O （GGNK） glasses doped with Er3＋. The GGNK glasses were characterized by differential scanning calorimetry （DSC）, Raman spectra, absorption and infra- red-visible fluorescence spectra. Measured DSC result showed that these glasses possessed an excellent stability （AT=188.6 ℃）. The relationship between glass composition and Judd-Ofelt intensity parameters and other optical properties of Er3＋, such as the absorption and stimulated emission cross-sections, were clarified. Meanwhile an intense broadband 1.53μm emission with a full width at half- maximum of 51 nm and peak emission cross-section of 9.32×10^-21 cm2 of Er3＋-doped GGNK glass was obtained upon 980 nm di- ode-laser excitation. Effects of K2O replacing Na2O on the thermal stability and spectroscopic properties were investigated. It was found that the incorporation of K2O into Er3＋-doped Ga2O3-GeO2-Na2O glass could effectively improve the 1.53 μm emission luminescence. The results showed that GGNK glass might be more attractive host material for their application in C-band optical fiber amplifiers.

Spectroscopic properties and energy transfer of Nd^(3+)/Ho^(3+)-doped Ga_2O_3-GeO_2 glass by codoping Yb^(3+) ion

This study presented the luminescence properties of Nd^3＋/Yb^3＋/Ho^3＋ dopant ions inside a host based on Ga_2O_3-GeO_2-Li_2O（GGL） glass. The measured differential scanning calorimetry result showed that GGL glass exhibited excellent stability against devitrification with ？T=135 oC. Obvious 543 and 657 nm emissions were observed in Nd^3＋/Ho^3＋-codoped sample. The incorporation of Yb^3＋ into Nd^3＋/Ho^3＋-codoped glass system had resulted in enhanced upconversion emission intensity under the excitation of 808 nm and/or 980 nm laser diode（LD）. The possible mechanisms and related discussions on this phenomenon were presented. It was noted that the presence of Yb^3＋ yielded an enhancement about 7 and 11 times in the 543 and 657 nm emission intensities respectively under 808 nm excitation due to the energy transfer from Nd^3＋ to Ho^3＋ via Yb^3＋ ion. Here Yb^3＋ played a major role as a bridging ion. While enhanced 543 and 657 nm emission intensities under the excitation of 980 nm LD originated from the sensitization effect of Yb^3＋. Our results showed that Nd^3＋/Ho^3＋/Yb^3＋ triply doped GGL glass might be a promising candidate for the development of visible-laser materials.

Tm^(3+)/Er^(3+)/Yb^(3+)掺杂的镓锗酸盐玻璃光谱性能及能量传递

采用熔融淬冷法制备得到透明的Tm^(3+)/Er^(3+)/Yb^(3+)掺杂镓锗钠玻璃。对比研究了808 nm和980 nm激发下Tm_2O_3含量对样品可见-红外光学光谱特性的影响。结合稀土离子能级结构,分析了Tm^(3+)、Er^(3+)和Yb^(3+)离子之间的能量传递机制。结果表明:在808 nm和980 nm的激发下,Tm^(3+)/Er^(3+)/Yb^(3+)掺杂样品中均观察到了473,655,521,544 nm的蓝、红和绿光。在808 nm激发下,随着Tm^(3+)浓度的增加,Tm^(3+):1 800 nm和Er^(3+):1 530 nm发射强度的比率I1.8/I1.53逐渐增大。由于在Tm^(3+)和Er^(3+)间的能量传递有效地改变了红光和绿光的发射强度,473,521,655 nm的发光强度呈现先升高再降低的趋势,在Tm_2O_3掺杂摩尔分数为0.3%时达到最大值。而在980 nm激发下,由于Yb^(3+)对Er^(3+)和Tm^(3+)的能量传递起主要作用,使得其上转换红光(655 nm)、绿光(521 nm和544 nm)和蓝光(473 nm)的发光强度高于808 nm激发下的上转换发光。

敏化剂离子对Tm^(3+)掺杂的镓锗玻璃1.47-μm发光特性研究

报道了Tm3+掺杂的15Ga2O3-75Ge O2-10Na2O玻璃1.47-μm发光,应用Judd-Ofelt理论计算了玻璃的强度参数t(t=2,4,6)、自发辐射几率A、荧光分之比β等各项光谱参数以及峰值发射截面σepeak。通过测量光谱性能研究了敏化剂离子(Ho3+,Tb3+,Sm3+,Dy3+)掺杂浓度对Tm3+离子1.47-μm波段发光性能的影响,分析了Tm3+和这些敏化剂离子之间的能量传递过程。研究表明镓锗钠玻璃是适用于S波段光纤放大器的一种潜在基质材料,而掺杂一定浓度的敏化剂离子迅速降低了Tm3+:3F4能级的粒子数,而对3H4能级粒子数影响不大,极大地提高了Tm3+离子在1.47-μm波段的发光效率,且Tb3+是最有效的敏化剂离子。

Er^(3+)掺杂的镓锗酸盐玻璃系统结构及光学性能的研究

采用熔融淬冷法制备了新型的Ga_2O_3-GeO_2-Na_2O玻璃。测试了样品的差示扫描分析曲线、紫外/可见/近红外透过率、拉曼光谱和980nm泵浦下的红外及可见发光光谱。利用经典的Tauc方程计算了样品的光学带隙。研究发现Ga_2O_3的引入提高了玻璃的热稳定性,缩短了样品的紫外吸收截止边,增强了玻璃的直接和间接光学带隙。同时,拉曼光谱分析表明随着Ga_2O_3对GeO_2取代量的增加,集中在中频段447cm-1的拉曼峰强度降低,峰位向高频方向移动;高频段830cm-1和933cm-1处两峰向低频方向移动,玻璃系统的最大声子能量降低。摩尔百分比为5%的Ga_2O_3对GeO_2取代显著提高了Er^(3+)的1.53μm的发射强度,并抑制了其上转换发射强度。