Annealing behaviour of structure and morphology and its effects on the optical gain of Er^3＋/yb^3＋ co-doped Al2O3 planar waveguide amplifier

Using transmission electron microscopy （TEM） and x-ray diffraction analysis, we have studied the structural and morphological evolution of highly Er/Yb co-doped A1203 films in the temperature range from 600℃-900℃. By comparison with TEM observation, the annealing behaviours of photoluminescence （PL） emission and optical loss were found to have relation to the structure and morphology. The increase of PL intensity and optical loss above 800℃ might result from the crystallization of amorphous Al2O3 films. Based on the study on the structure and morphology, a rate equation propagation model of a multilevel system was used to calculate the optical gains of Er-doped Al2O3 planar waveguide amplifiers involving the variation of PL efficiency and optical loss with annealing temperature. It was found that the amplifiers had an optimized optical gain at the temperature corresponding to the minimum of optical loss, rather than at the temperature corresponding to the maximum of PL efficiency, suggesting that the optical loss is a key factor for determining the optical gain of an Er-doped Al2O3 planar waveguide amplifier.

含双噻唑基聚合物的合成及电流变性能研究

采用 2 ,2′ 二氨基 4,4′ 双噻唑与联苯胺合成一种含有双噻唑基的共轭聚合物 ,通过红外、扫描电镜、热重分析等测试了该物质的结构及热稳定性等 ,并通过将聚合物分别分散在硅油和溴代二苯甲烷中制备电流变体 ,测试其电流变性能。结果表明 :含双噻唑基的共轭聚合物作为电流变体的分散相表现出了良好的电流变性能 ,同时发现分散相和分散介质的密度相近时有利于电流变性能的提高。

含英咀华 推陈出新——从为学与处世谈孟二冬精神对传统文化的吸收与改造

从为学和处世两方面分析了孟二冬敬业与自得相结合、传统的淡泊名利与新型的淑世情怀相结合的精神内容;并在此基础上探讨了这种精神对传统文化的吸收与改造,以及对当代的精神文明建设的重要意义。