Heating of high-power laser diode arrays: from temperature data to power management and failure mechanisms

Summary form only given. High-power laser diode arrays (LDA) are important radiation sources for a number of applications. Device operation usually happens under heavy thermal load. Thus for reducing failure sensitivity, detailed insight into the power balance of the devices is of great importance. We report on new facet temperature measurements carried out in 808-nm emitting high-power LDA based on InAlGaAs/GaAs double quantum well structures. We determined temperature distributions along the line of the emitters in arrays as well as across the optical active layer of single emitters. A comparison of facet temperatures for different laser waveguide architectures such as graded index, step index, and large optical cavity is provided. Together with the bulk temperature, as well as the temperature of the submount close to the laser chip, we obtain extensive information on the temperature distribution in devices during high-power operation. A second series of experiments was aimed at getting insight into thermal processes accompanied with catastrophic optical damage. Using the set of experimental temperature data, FEM simulations enable us to consistently describe the power management of the device for various operation conditions.