Journal Article 7440-57-5 Bragg diffraction Gold Research Support, Non-U.S. Gov't Research Support, U.S. Gov't, Non-P.H.S. X-ray optics X-ray refractive lenses asymmetric monochromator broadband transmission of metallic gratings cavity-based X-ray free-electron lasers diamond crystals dynamical theory freely tunable polarization conversion high heat load inclined double-crystal monochromator non-coplanar diffraction polarization rotator of terahertz waves