Progress in the natural sciences has for centuries been intimately coupled to the development of optical instruments and light sources. The 1960s saw two important breakthroughs; the invention of light sources delivering coherent photon beams in the visible wavelength region, and the realization that incoherent light in the x-ray region was emitted from electron accelerators called synchrotrons. Visible lasers are now an indispensable tool for researchers in the physical and life sciences, and synchrotron radiation sources serve thousands of scientific users all over the world.
Ever since the appearance of the first laser, there has been a continuous push for shorter laser wavelengths, and ingenious schemes have been developed in attempts to beat the laws of quantum physics, which say that the shorter wavelength, the more difficult it is. By using electrons as the lasing medium, and by taking advantage of years of accelerator R&D for high-energy particle physics, it has finally become possible to device schemes for producing laser light in the x-ray region.
Efforts to build lasers in the x-ray region are now made in Europe, the US and Japan. In Europe, the XFEL project has started at DESY in Hamburg, and Sweden has decided to join this project.
Recognizing the international development of photon-based sciences, and identifying the potential for participating in this development for researchers in the Mälardalen region, the Royal Institute of Technology, Stockholm University, and Uppsala University has responded to the challenges by forming a Centre for Development and Research at Free Electron Laser Facilities. The FEL Centre is already heavily involved in work packages being undertaken for the XFEL in Hamburg.