Coherence properties of X-ray lasers and synchrotron undulator radiation

The third-generation synchrotron radiation source (TGSRS) can produce high-brightness, laser-like radiation in the soft- and hard-X-ray region; i.e., the TGSR produces tunable, partially coherent radiation with controllable polarization. Since no tunable soft-X-ray lasers exist yet, the TSRS is an excellent alternative to the X-ray laser for spectroscopy and microscopy, among other things. In this report, we will make a detailed comparison between radiation from existing X-ray lasers and undulator radiation in terms of coherence and other properties. Some interesting examples of SR X-ray spectroscopy and microscopy will also be discussed.