Statistical characterization of the lifetimes of continuously operated (Al,Ga)As double‐heterostructure lasers

The statistical distribution of lifetimes of routinely grown and fabricated continuously operated (Al,Ga)As double‐heterostructure lasers is presented and discussed. The 90 typical devices studied were operated as lasers in a dry‐nitrogen elevated‐temperature ambient (70 °C) until failure. The resulting median life, τm=750 h, and mean life, 〈τ〉=1370 h, extrapolate to τm=5.7 years and 〈τ〉=10.5 years at room temperature (22 °C) using a 0.7‐eV activation energy. The observed lifetimes are consistent with a model in which 17% of the lasers die prematurely as infant mortalities while 83% die by a mechanism well characterized by a lognormal distribution. The value of the standard deviation (σ=1.1) in lnτ is typical of other semiconductor devices.