Reliability-extrapolation methodology of semiconductor laser diodes: is a quick life test feasible?

The test duration of semiconductor lasers required for Telcordia reliability qualification is usually lengthy. An alternative accelerated life test to validate the reliability design is critical for the timely deployment of new products. In this paper, the results of fitting time-to-failure extrapolations based on experimental data from 500-5000-h measurements are compared. It is shown that, for buried-heterostructure lasers that exhibit gradual performance degradation, the lifetime predictions based on 500-1000-h experimental data are consistent with those based on 5000-h data. For ridge-type lasers, little degradation occurs; hence, an early reliability prediction is less accurate. The determining factors that affect the accuracy of the early reliability predictions are discussed.