高功率二极管激光器寿命测试

介绍了高功率激光二极管不同模式的失效机理，分析了激光二极管不同的寿命测试方法；在冷却水温20℃和实际工作温度下分别对封装的激光器进行了寿命测试。根据试验结果得出退化率，推算出准连续二极管激光器在水温20℃，电流90A，占空比为10%（500Hz，200μs）时，平均激光工作寿命为2.19×109次脉冲；冷却水温35℃时，其平均激光工作寿命下降为1.65×109次脉冲。由实验结果分析得出，高功率激光器封装工艺中的焊料沉积和多层焊接技术，以及工作环境温度是影响激光器可靠性和寿命的关键因素。

Spot size measurement of new type X-ray source designed

The X-ray source based on electron accelerator is the foundation of high energy industrial CT(ICT). A new type of small spot size SW electron linac was designed with high space resolution. This paper discusses that spot size of radial source influence on the imaging quality, and analyzes the physical reason that at high energy the small hole method wasn't suit for the measurement of spot size, it also gives four kinds of measurement method for this type of high energy X-ray source spot size and the analysis of the experiment results. The measurement results show that spot size of the new type accelerator X-ray source is about 1.4mm, and the limited space resolution is 2.5lp/mm.