By utilizing the active Kirkpatrick–Baez optical system in collimation mode coupled with a spiral zone plate, orbital angular momentum (OAM) beams have been successfully generated and characterized. The reported findings are relevant for future experiments on OAM structured beams.

Grating configurations for compressing free-electron-laser pulses are discussed.

A benchmark experiment that demonstrates the shortening of hard X-ray pulses in a synchrotron-based optical pump–X-ray probe measurement is reported.

The X-ray natural circular dichroism of langasite crystal La₃Ga₅SiO₁₄ near the Ga K-edge is described in terms of the gyration tensor formalism. The experimental spectra are compared with the results of ab initio calculations that, for the first time, have allowed one to disentangle the contributions from Ga atoms in different Wyckoff positions.

Double optical functionality of a ruthenium nitro­syl compound is achieved by the combination of photoswitching of the nitro­syl ligands, giving rise to photochromic behaviour, with the second-harmonic generation enabled by the alignment of the molecular dipoles in the non-centrosymmetric structure of trans-[RuNO(NH₃)₄F]SiF₆.