Editorial to the special issue on measurement techniques in extreme environments

Assessing the performance of materials and structures in extreme environments relies heavily on measurement technologies. Among these, optical measurement techniques have emerged as the optimal solution and the preferred metrology method due to their non-contact and non-destructive advantages. This special issue highlights the latest developments and applications of optical and laser-based measurement technologies in extreme environments. As of May 2025, this special issue has finalized the inclusion of 29 outstanding papers from around the world. These submissions cover advancements in optical and laser measurement technologies, their applications in extreme environments, integration with technologies such as artificial intelligence and neural networks, and other research related to extreme-environment measurement techniques. In the current era, the term “extreme environments” is no longer confined to deep space or reactor core scenarios. With the increasing integration and multifunctionality of instruments and equipment across industries, many materials and structures endure increasingly complex loads and frequently operate under extreme conditions. Assessing the performance of materials and structures in extreme environments relies heavily on measurement technologies. Among these, optical measurement techniques have emerged as the optimal solution and the preferred metrology method due to their non-contact and non-destructive advantages.