Researchers contributed to a deeper understanding of free electron laser physics by evaluating the interaction between an ultraviolet laser and a relativistic electron beam in a pure dipole magnet. The team used a 266-nm laser at the soft x-ray FEL test facility to modulate an 800-MeV electron beam….The results showed that a short dipole magnet can serve as an effective tool for introducing energy modulation of relativistic electron beams, effectively tailoring FEL pulse properties by introducing precise bends in the pathway.