Study on Stress Characteristics of High Power

高功率半导体激光器具有体积小、重量轻、效率高、寿命长等诸多优点，它 主要应用于泵浦固体激光介质、激光加工、空间光通信等国防军事和工业领域。 而高功率半导体激光器阵列中存在的键合应力会降低器件的工作寿命、造成阵列 近/远场发生畸变、影响器件的偏振特性、使得阵列的整体性能恶化，从而影响 其广泛应用。因此，对高功率半导体激光器阵列键合应力分布的研究和测量，有 利于改善封装结构和工艺，进而提高器件性能，具有十分重要的实用价值和科学 意义。 本文主要研究工作包括： 对高功率半导体激光器阵列的远场发散角、“smile”测量和热阻测试中， 提出利用CCD 拍照法代替原有的旋转电机法来进行远场发散角测试； 在“Smile”的测试实验中，主要从两种对“Smile”的近似条件出发， 由测试数据计算实际“Smile”的值，并分析了垂直放置的慢轴发散透镜 对结果的影响；提出了利用光谱偏移测量准连续工作高功率半导体激光 器阵列热阻的不同计算方法。 对半导体激光器阵列电荧光偏振度和应力关系进行了实验研究，测试了 偏振度随驱动电流的变化趋势，定性地观测了外加压力和半导体激光器 阵列电荧光偏振度的关系；对多个不同封装的半导体激光器阵列的电荧 光偏振度进行了测试，检测到多个阵列的电荧光偏振度不均匀分布的现 象，并对由此推测的应力分布进行了分析。 对多个高功率半导体激光器阵列在不同驱动电流水平下的横向波长分 布进行了实验测试，发现多个器件的横向波长呈“V”字型分布，还有 少数的不规则分布，解释了封装后器件光谱展宽的原因，提出了线性应 力分布模型，较好的解释了这种“V”型波长分布High Power Laser Diode (HPLD) have many merits such as small volume, low weight, high efficiency and long lifetime, it’s mainly used in military and industrial fields, for example, pumping solid-state laser materials, laser manufacturing and deep space optical communication, etc. . The bonding stress in the HPLD array may shorten the operational lifetime, lead the distortion of near and far-field, change the degree of polarization which makes it difficult for polarization coupling. Therefore, study on the distribution of the bonding stress is a very important practical and scientific value for improving the packaging structure and technology which can enhance the HPLD’s performance. The mainly work of the thesis can be summarized as follows: In the testing of the far-field divergence angle, “smile” and thermal resistance, a new test method of far-field divergence using CCD camera substituting the traditional components is proposed. The influence of the cylindrical lens on the testing results is analyzed in the “smile” measurement. The different calculated methods of the QCW HPLD’s thermal resistance using wavelength red shifts are introduced. The relationship between electro-fluorescence degree of polarization (DOP) and the stress is studied experimentally. The DOP of HPLD is tested at different driving current. The changing of electro-fluorescence DOP under applied pressure is observed. The electro-fluorescence DOP of several HPLD arrays in different packaging ways are tested, there are non-uniform DOP distribution according to different stress. The transverse wavelength distribution of dissimilar packaging HPLD at different driving currents are tested, the results indicated that the distribution of a great number of HPLD is “V”-type, others is irregularly distribution, this explains the spectra broadened reason after packaged of the HPLD. A linear stress distribution model is proposed, and the model can explain the “V”-type distribution well