CCD-based thermoreflectance imaging and finite element modeling are used to study the two-dimensional (2D) temperature profile of a junction-down broad-area diode laser facet subject to back-irradiance. By determining the temperature rise in the active region (ΔΤAR) at different diode laser optical powers, back-irradiance reflectance levels, and back-irradiance spot locations, we find that ΔΤAR increases by nearly a factor of three when the back-irradiance spot is centered in the absorbing substrate approximately 5 μm away from the active region, a distance roughly equal to half of the back-irradiance spot FWHM (9 μm). This corroborates prior work studying the relationship between the back-irradiance spot location and catastrophic optical damage, suggesting a strong thermal basis for reduced laser lifetime in the presence of back-irradiance for diode lasers fabricated on absorbing substrates.

中文翻译：

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受背辐照影响的高功率二极管激光器的热成像

基于 CCD 的热反射成像和有限元建模用于研究受背照度影响的结向下大面积二极管激光器面的二维 (2D) 温度分布。通过确定不同二极管激光器光功率、背辐反射率水平和背辐光斑位置下有源区 (ΔTAR) 的温升，我们发现当背辐光斑为以吸收基板为中心，距有源区约 5 μm，距离大致等于背面辐照光斑 FWHM (9 μm) 的一半。这证实了先前研究背面辐照光斑位置与灾难性光学损伤之间关系的工作，