Extremely ultrashort and short-wave light pulses are generated with the aid of the traveling-wave Thomson scattering process. Dispersive elements are arranged between an electron, particle, or radiation source, which is synchronized with a laser system, and an optical element that focuses in a direction. The device is used to superpose a pulse-front tilted light pulse of high power with an ultrashort pulse of relativistic electrons in a laser-line focus. By varying the laser pulse-front tilt, narrow-band radiation pulses in a wide wavelength range from EUV to X-ray wavelengths and having a high number of protons are obtained, and the bandwidth and coherence properties can also be modified. The system can be used, among other things, in EUV lithography, in the planning and optimal design of laser systems and electron sources, in material analysis by phase contrast imaging, and in superconductor research. The assembly is smaller and cheaper than current comparables.