Extremely high electromagnetic field intensity, so-called extreme light, is produced at the focus of an ultra-high-peak power laser, such as UNL’s Diocles laser. During its interaction with matter, light at this extreme limit can accelerate electrons to relativistic velocity in a single optical cycle, resulting in a host of novel research opportunities and technologies. In the area of nonlinear quantum electrodynamics, the physics of highly radiating electrons can now be studied. In the area of fundamental laser-plasma interactions, a new line of inquiry into relativistic optics has been launched. Extreme light also leads to novel electron accelerators and x-ray light sources. One such novel technology is the Diocles-laser-driven x-ray synchrotron. Its unique performance characteristics include: (1) an unprecedentedly large energy tunability range (keV to MeV), (2) micron-scale radiation source size, and (3) ultra-short pulse duration (< 10 femtoseconds). These features allow matter to be probed with spatial and temporal resolutions that are both—simultaneously—on the atomic scale. This has relevance to advanced radiological applications, especially in the areas of materials science, biomedicine, nuclear physics and engineering, defense, and homeland security.