Catastrophic optical damage (COD) is one of the processes limiting the lifetime of high-power laser diodes. The understanding of this degradation phenomenon is critical to improve the laser power and lifetime for practical applications. In this Letter, we analyze the defect propagation inside the cavity of quantum well (QW) high-power laser diodes presenting COD. For this, we studied the effect of highly localized thermal gradients and degraded regions on the laser field distribution. Finite element method (FEM) simulations are compared to experimental cathodoluminescence (CL) measurements. The presence of micrometric hot spots inside the QW induces the thermal lensing of the laser field. The laser self-focusing inside the cavity eventually generates a new hot spot, and, in a repetitive way, a sequence of hot spots would be created. This would account for the propagation of the dark line defects (DLDs) that are characteristic of this degradation mode.

中文翻译：

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热透镜和微米级退化区域对大功率激光二极管灾难性光学损伤过程的影响

灾难性的光学损伤（COD）是限制高功率激光二极管寿命的一种方法。对于实际应用，了解这种退化现象对于提高激光功率和使用寿命至关重要。在这封信中，我们分析了存在COD的量子阱（QW）大功率激光二极管腔体内的缺陷传播。为此，我们研究了高度局部化的热梯度和退化区域对激光场分布的影响。将有限元方法（FEM）模拟与实验性阴极发光（CL）测量进行比较。QW内部存在微米级热点，引起激光场的热透镜化。腔体内的激光自聚焦最终会产生一个新的热点，并以重复的方式产生一系列热点。