The application of light in several different industries has become more sophisticated as technologies advance. Knowing how the light interacts with its process is now crucial not only in the development of the process, but in the application, operation, and maintenance of the process as well, specifically in more recent times, as Industry 4.0 practices continue to be realized for their worth. For instance, not only is it important for a laser user to understand how the laser source behaves before it is placed into an additive manufacturing system, it is also important to ensure that the laser performs consistently during the relatively longer processing of parts. The technology behind the tools to measure and analyze laser performance has advanced as well. This tech talk will investigate high-power laser welding of copper, laser-based additive manufacturing processes, automotive LiDAR systems, and how performance measurement solutions have helped solve problems in application development as well as laser operation and maintenance.