Novel “XFELO” laser system produces razor-sharp X-ray light
For the first time, researchers have amplified X-ray light multiple times in a resonator cavity, in a way highly similar to traditional lasers. With great success: the new technique delivers extremely energetic X-ray pulses for high-precision experiments. This development opens up entirely new possibilities for research in physics, chemistry, or biology. The system is called “XFELO”. Researchers from European XFEL, DESY and Hamburg University have published their findings in the latest edition of the journal Nature.
The team of engineers and scientists have shown for the first time that a hard-X-ray cavity can provide net X-ray gain, with X-ray pulses being circulated between crystal mirrors and amplified in the process, much like happens with an optical laser. The result of the proof-of-concept at European XFEL is a particularly coherent, laser-like light of a quality that is unprecedented in the hard X-ray spectrum. Lasing inside a cavity had been challenging to achieve with short-wavelength X-rays for a variety of reasons, including – on a basic level – that the nature of the light makes it difficult to reflect the beam at large angles. The “XFELO” (short for: X-Ray Free-Electron Laser Oscillator) technique opens new perspectives for scientific investigations, from ultrafast chemical reactions to detailed analyses of the smallest biological structures.
Read more on the European XFEL website
Image: Illustration of the XFELO system: a hard X-ray pulse (red) is reflected by a set of diamond mirrors and oscillates through arrays of magnets, so called undulators. On each roundtrip the pulse meets a new electron bunch (blue), which emits X-rays while passing through the undulators on a slalom course.
Credit: European XFEL