SASE (Self-Amplified Spontaneous Emission)

Self-Amplified Spontaneous Emission (SASE) is a process used in free-electron lasers to generate extremely intense, coherent light, often in the X-ray spectrum. It begins with a high-energy electron beam passing through a special magnetic structure called an undulator. As the electrons wiggle, they emit light spontaneously. This emitted light then interacts with the electrons, causing them to become more synchronized and emit even more light. The process rapidly amplifies the light, producing a powerful, laser-like beam without the need for external seed signals. SASE enables scientists to access high-energy photons for advanced research.