Novel diamond X-ray crystal optics for synchrotrons and X-ray free-electron lasers

• Comprehensive review of novel diamond crystal optics for synchrotrons and XFELs
• Details of practical importance on fabrication and characterization methods of diamond crystals with suitable quality
• New insights on further development of diamond technology for applications in X-ray optics

The most common applications of diamond crystals in X-ray optics are high-heat-load monochromators for synchrotron beamlines and phase retarders for polarization control. Here, less common applications of diamond at the frontier of X-ray crystal optics are reviewed and summarized. These include a sub-meV-bandwidth X-ray monochromator with high spectral efficiency [1] and all-diamond optical assemblies for a beam-multiplexing double-crystal monochromator at the Linac Coherent Light Source [2]. Also, novel applications for the realization of fully coherent hard X-ray sources are discussed, such as, diamond crystal optics for self-seeding of hard X-rays in the Linac Coherent Light Source [3,4] and Bragg mirrors for the highly anticipated X-ray free-electron laser oscillator [5,6]. These examples present diamond as a material for the next generation of X-ray optics, optics which can provide unique characteristics and capabilities to modern X-ray sources. In addition, details of practical importance on fabrication and characterization methods of diamond crystals with the suitable quality are presented.