Accelerated life tests (ALTs) are aimed at revealing and understanding the physics of the expected or occurred failures. Another objective of the ALTs is to accumulate representative failure statistics. Thus, ALTs are able to both detect the possible failure modes and mechanisms and to quantitatively evaluate the roles of the phenomena and processes that might lead to failures. Adequately designed, carefully conducted, and properly interpreted ALTs provide a consistent basis for obtaining the ultimate information of the reliability of a product - the probability of failure. ALTs can dramatically facilitate solutions to the problems of cost effectiveness and time-to-market. Because these tests can help a manufacturer to make his device a product, they should play an important role in the evaluation, prediction and assurance of the reliability of photonics devices and systems. In the majority of cases, ALTs should be conducted in addition to the qualification tests, which are required by the existing standards. There might be also situations, when ALTs can be used as an effective substitution for qualification tests. Whenever possible, ALTs should be used as a consistent basis for the improvement of the existing qualification specifications.
In this discussion, we describe different types (categories) of accelerated tests, with the emphasis is on the role that ALTs should play in the development, design, qualification and manufacturing of photonics products. The case of a laser welded photonic package assembly is used to illustrate some of the concepts addressed.