电致发光用于大功率半导体激光器失效模式分析

利用电致发光（EL）的方法，研究了突然失效的975 nm大功率应变量子阱激光器。起初，我们以为激光器失效是由于腔面发生了突然光学灾变（COMD）。然而，通过EL实验，发现其中一部分激光器腔面没有任何损伤，而内部发生了突然光学灾变（COBD），为工艺的进一步改善指明了方向。对90只发生COD的激光器进行EL成像，发现暗线缺陷（DLD）起始于腔面或是激光器内部。DLD是严重的非辐射复合区，通常沿着有源区延伸出几个分支，造成激光器功率急剧下降。详细分析了不同COD模式的特征并进行了对比。并进一步分析了两种典型COD模式发生的原因，然后给出了抑制COD和提高大功率半导体激光器性能的建议。

Failure Mode Analysis of High-power Laser Diodes by Electroluminescence

We performed failure mode analysis (FMA) on the suddenly failed high-power 975 nm strained quantum well diode lasers. At first, we believed that the lasers suffered catastrophic optical damage (COD) at the mirror facets, which is called COMD. However, by electroluminescence (EL), we found that some lasers suffered COD only in the bulk without any damage at both facets, which is called COBD, thus guiding our further improvement. Among all the 90 lasers that suffered COD, the EL images demonstrate that the dark line defects (DLDs) can originate from the facets or the bulk. These DLDs are highly non-radiative region and usually confined in the active region with several branches, which leads to the dramatic decrease of the optical power. And to the different COD modes, the common features of DLDs were interpreted and compared in detail. Furthermore, the causes to the two typical COD modes were analyzed, and suggestions were made to suppress the COD process and further improve the high-power laser diodes.