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For high-performance optical data storage applications, AIGaAs/GaAs diode lasers were stressed at various power levels, temperatures, and operating conditions. The devices tested were V-channeled structures mounted with the junction side down. These lasers came from a single production run to eliminate the statistical variances associated with multilot tests. Cumulative failure plots for cells at 30 mW stressed at 65°C and 40 mW stressed at 55 and 65°C show that two failure mechanisms are present, which we designated as intrinsic and wear-out failure regions. Using the data from the wear-out region and assuming an Arrhenius model for the temperature dependence of the reliability function, we found that the activation energy for this lot of lasers is 0.37 eV. From this evaluation, we project a median lifetime of 3.4 khrs for 40 mW operation at 35°C, and a median lifetime of 36.7 khrs at 30 mW and 35°C, which is an order of magnitude greater. Fot :4 power model where the median lifetime is proportional to power raised to the -n, we calculated that n is 4.3 for powers between 30 and 40 mW. Other data to be discussed was accumulated from low-power continuous-wave and pulsed stress cells. In addition, failure analysis results correlated with the various failure regions will be presented. All the devices were fully characterized prior to stressing, and throughout the stress period they were periodically characterized for changes in operating current at 7 mW and 30 mW, for parallel and perpendicular far-field distributions, and for astigmatic length. To our knowledge, this is the first experimental data that tracks these optical properties over the life of a laser diode. With the exception of the drive current to maintain a given optical power, all other electro-optic properties exhibit stability throughout the diode lasers' lifetime. The data also shows that there is no precursor to failure. Our results show that acceptable reliability targets can be met for high-performance optical storage applications as long as the operating temperature is maintained below 35°C and the optical power is limited to 30 mW.
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