25 Gb/s粗波分复用分布式反馈激光器的可靠性研究

高速波分复用分布式反馈（DFB）激光器是数据通信的核心器件,其可靠性影响了整个通信系统的可靠性。对自主研发的25 Gb/s 4波长粗波分复用（CWDM4） DFB激光器进行了2种老化筛选（Burn-in）实验和失效分析,并采用三温法推算了激光器的工作寿命。实验结果表明：对激光器采用光加速（25℃、100 mA）和温度加速（100℃、75 mA）相结合的Burn-in方法能够有效激发薄弱激光器的早期失效特征;采用三温法推算激光器在60℃、45 mA环境下长期工作的实际寿命至少为17年。     

2195铝锂合金超声TIG焊的组织与性能分析

采用了普通TIG焊和超声复合TIG焊对2 mm厚度的2195铝锂合金进行了平板对接焊,并对两种焊接接头的显微组织和力学性能进行了研究. 结果表明,由于超声的作用效果,超声TIG焊的焊缝具有更加致密的组织,熔合区附近的等轴细晶区区域较宽;拉伸性能测试表明,超声TIG焊接头具有较高的拉伸性能,接头强度系数比普通TIG焊提高6.7%,断后伸长率提高1.36%,拉伸接头均断裂在热影响区硬脆的晶界相内,显微硬度测试表明超声TIG焊接头受热影响软化区域较窄.     

Pulsed TIG welding-brazing butt joints of aluminum-stainless steel thin plates with different fillers

Aluminum and stainless steel plates with 1.5 mm thickness are joined by pulsed TIG welding-brazing process with ER1100, ER4043 and ER2319 fillers, separately. Good weld formation can be obtained by adjusting appropriate pulse parameters. The effects of the fillers on that the thickness of the intermetallic compound （ IMC ） and tensile strength of the joints are investigated. SEM results indicate layer with ER2319 filler is about 2 ~m, which is thinner than 2. 5 p~m of ER1100 filler and 3.5 txm of ER4043 filler. Moreover, the element distribution in both IMCs and welded seams with three fillers are different because of the different compositions of fillers. The results of mechanical property tests suggest that the joint strength with ER2319 filler is the highest, while the joint impact energy is the lowest. The joint with ERllOO filler exhibits the best comprehensive mechanical pet.formanee.     

垂直腔面发射激光器中位错形成及扩展特性分析

垂直腔面发射激光器（VCSEL）具有成本低、速率高、功耗低和易于集成等优点,在短距离数据通信等领域具有广泛的应用。随着使用寿命、失效率等要求的不断提高以及器件应用需求的不断增大,VCSEL的可靠性受到了人们的广泛关注。研究发现,VCSEL失效的主要原因与位错的产生和扩展有关。为了提高器件的可靠性,对VCSEL内位错形成的原因进行分析,并系统介绍了位错扩展的动态特性和内在机理。