发光学报, 2018, 39 (11): 1519, 网络出版: 2018-12-25
热离子交换型铝锗酸盐波导玻璃中钬离子的1.2 μm近红外荧光发射
1.2μm Near Infrared Fluorescence Emission of Holmium Ions in Thermal Ion-exchanged Aluminum Germanate Waveguide Glasses
钬离子 钾钠热离子交换 铝锗酸盐波导玻璃 近红外发射 Ho3+ ions K+-Na+ thermal ion-exchanged aluminum germanate waveguide glasses near-infrared emission
摘要
采用高温熔融法制备了适用于钾钠离子交换波导的钬离子掺杂铝锗酸盐玻璃, 并对热离子交换玻璃样品的波导折射率分布和红外光谱特性进行了表征。实验结果表明, 在390 ℃的KNO3熔盐中热离子交换4 h时, 波导玻璃折射率最大改变量为0.006 9, K+-Na+热离子交换有效扩散深度为7.802 μm, 有效扩散系数达0.063 μm2/min。K+-Na+离子交换有效扩散系数比磷酸盐玻璃低, 与MP19硅酸盐玻璃相当, 但明显高于BK7玻璃和硼硅酸盐玻璃, 其热离子交换过程易于控制。在644 nm泵浦光下可观察到Ho3+归属于5I6→5I8的1.196 μm近红外有效发射, 最大受激发射截面为2.30×10-21 cm2。当Ho3+在5I6能级的分数因子超过0.6时, 增益截面达10-21 cm2量级以上。有效的近红外荧光发射和稳定的波导性能表明钬掺杂铝锗酸盐玻璃是~1.2 μm波导激光器潜在的增益介质。
Abstract
Ho3+ doped aluminum germanate glasses adapting for K+-Na+ ion-exchanged waveguide were fabricated by high temperature melting technique. The thermal ion-exchanged waveguide refractive index profile and infrared spectral characteristic of the glasses were measured. These experimental results reveal that the maximum change of refractive index in waveguide glasses is 0.006 9 when Ho3+ doped aluminum germanate glasses are immersed in KNO3 molten salt at 390 ℃ for 4 h. Effective diffusion depth and coefficient of K+-Na+ thermal ion exchange are 7.802 μm and 0.063 μm2/min, respectively. K+-Na+ effective diffusion coefficient in aluminum germanate glass is lower than that in phosphate glass and approximately equals to that in MP19 silicate glass, but significantly higher than those in the BK7 glass and borosilicate glass, which indicates the thermal ion-exchanged process can be controlled easily. Effective 1.2 μm near infrared emission belonging to 5I6→5I8 transition could be observed under 644 nm pump whose the maximum stimulated emission cross-section at 1.196 μm is derived to be 2.30×10-21 cm2. For the 5I6→5I8 transition of Ho3+, the gain cross-section achieves a magnitude of 10-21 cm2 when fraction factor P exceeds 0.6. Effective near-infrared fluorescence and perfect waveguide performance demonstrate that Ho3+ doped aluminum germanate glass is a kind of potential gain medium in ~1.2 μm waveguide laser device.
杨佳心, 赵昕, 张竞辉, 林海. 热离子交换型铝锗酸盐波导玻璃中钬离子的1.2 μm近红外荧光发射[J]. 发光学报, 2018, 39(11): 1519. YANG Jia-xin, ZHAO Xin, ZHANG Jing-hui, LIN Hai. 1.2μm Near Infrared Fluorescence Emission of Holmium Ions in Thermal Ion-exchanged Aluminum Germanate Waveguide Glasses[J]. Chinese Journal of Luminescence, 2018, 39(11): 1519.