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Degradation of high power laser diodes is related to defect formation in the active parts of the laser. Extended defects can develop both at the facets, and inside the cavity. Their characterization is necessary for understanding the mechanisms driving the degradation. Cathodoluminescence is very useful for studying defects in degraded lasers. The main degradation mechanisms are discussed, supported by a thermomechanical model.

In the past, a lot of experimental studies have been devoted to creep-fatigue interactions in austenitic stainless steels. Tests have been carried mainly at temperatures of at least 600 °C and at high applied strains, which are supposed to be the most damaging. The present work is dedicated to mechanical tests, TEM observations and lifetime predictions at 550 °C which corresponds to the real industrial temperature in Liquid Metal Fast Breeder Reactors. It is shown that if pure fatigue test results are close to those performed at 600 °C, some of the creep-fatigue results are different, particularly for small applied strains which correspond once more to the industrial conditions. In the 0.25–0.3% strain amplitude range, the stress is larger with hold time than without whatever is the hold time up to 5 h. The numbers of cycles to failure are greatly reduced and no saturation with the hold time is observed, contrary to higher temperature results. The stress–strain behaviour is discussed considering several high temperature mechanisms such as ageing, recovery and viscoplasticity and using TEM observations and stress partitioning into kinematic, isotropic and thermal stresses. Finally, a simple linear damage accumulation model is applied to the 550 °C and 600 °C tests, using the measured stresses. The stress dependence on hold time can partly explain the observed failure results on fatigue life.

The development of optical communications has generated a huge expansion of the use of optoelectronic components for transmission, mainly for transmitters, receivers and optical amplifiers. This development has been possible because the technology is now mature, meaning that performance and reliability have greatly improved over the last years. This paper will give a short history of the evolution of the reliability of optical components, and will describe the current status. Main failures mechanisms analyses and a comparison between reliability calculations and actual field operational results will be made.

Qualification of opto-electronic devices is a mandatory but complex activity to perform in a fast changing technical environment and under a strong market pressure. In this paper, we analyze the advantages and drawbacks of the traditional qualification approach based on both end-development tests defined by international standards and statistical reliability calculations. We explain how we are adapting our qualification practices towards risk assessment methods and design for reliability process. Looking at the future trends or telecom opto-electronic devices, possible challenges that qualification activity will have to face are finally discussed.