Comparison of spatial coherence properties of EUV/soft X-ray undulator, laser and high-order harmonic generation sources

Summary form only given. Motivation for the development of coherent X-ray sources comes from many areas of science and technology. To date, undulators in third-generation synchrotrons are leading sources for high average power coherent radiation in extreme ultraviolet (EUV)/soft X-ray region, while there are also great efforts to make compact size EUV/soft X-ray sources. Two active research fields are soft X-ray lasers and high-order harmonic generation (HHG). Recently, there have been significant progresses in both fields.