用于光纤通信的1.55μmDFB激光器的可靠性分析

对用于光纤通信的InP基1.55 μm DFB激光器的可靠性进行了研究.测试并分析了100 ℃时100 mA和150 mA 2种电流应力条件,经过1 700 h老化,测试分析了激光器特性随时间的变化情况,拟合出在100 ℃,150 mA条件下的激光器寿命在1 000 h小时左右.根据实验结果对比,提出了一种新的利用温度、电流两个加速度变量同时进行加速老化,快速估计激光器寿命并分析其可靠性的方法.对新的寿命估算方法进行了详细的讨论.

用推广的平面波展开展法检验平面内极化的电子子带跃迁

把平面波展开包络函数的方法推广到求解8带的哈密顿量,使它同时包括Г~c_1和Г~v_(15).在这种方法里,可以考虑反演不对称性、能带的非抛物性、有效质量不连续性以及 自旋-轨道耦合等效应的影响.作为应用,计算了两个量子阱结构的子带和光跃迁概率.实验上在这两个结构中观察到了平面内极化的电子子带跃迁.计算表明这种跃迁的概率很小.实验上观察到的平面内极化的电子子带吸收可能有其他的机制.

Single steady frequency and narrow line width external cavity semiconductor laser

A single longitudinal mode and narrow line width external cavity semiconductor laser is proposed. It is constructed with a semiconductor laser, collimator, a flame grating, and current and temperature control systems. The one facet of semiconductor laser is covered by high transmission film, and another is covered by high reflection film. The flame grating is used as light feedback element to select the mode of the semiconductor laser. The temperature of the constructed external cavity semiconductor laser is stabilized in order of 10(-3)degreesC by temperature control system. The experiments have been carried out and the results obtained-the spectral fine width of this laser is compressed to be less than 1.4MHz from its original line-width of more than 1200GHz and the output stability (including power and mode) is remarkably enhanced.

Studies of 6H-SiC devices

Silicon carbide (SiC) is recently receiving increased attention due to its unique electrical and thermal properties. It has been regarded as the most appropriate semiconductor material for high power, high frequency, high temperature, and radiation hard microelectronic devices. The fabrication processes and characterization of basic device on 6H-SiC were systematically studied. The main works are summarized as follows:The homoepitaxial growth on the commercially available single-crystal 6H-SiC wafers was performed in a modified gas source molecular beam epitaxy system. The mesa structured p(+)n junction diodes on the material were fabricated and characterized. The diodes showed a high breakdown voltage of 800 V at room temperature. They operated with good rectification characteristics from room temperature to 673 K.Using thermal evaporation, Ti/6H-SiC Schottky barrier diodes were fabricated. They showed good rectification characteristics from room temperature to 473 K. Using neon implantation to form the edge termination, the breakdown voltage was improved to be 800 V.n-Type 6H-SiC MOS capacitors were fabricated and characterized. Under the same growing conditions, the quality of polysilicon gate capacitors was better than Al. In addition, SiC MOS capacitors had good tolerance to gamma rays. (C) 2002 Published by Elsevier Science B.V.