A Fabry-Perot interferometer for sub-meV x-ray energy resolution (invited)

Abstract

The optical theory of Fabry-Perot interferometers (FPIs) for x rays using dynamically diffracting thin perfect crystals as reflectors is developed. Application to a device using high diffraction orders in silicon crystals of thickness of the order of 100 μm or more shows that energy resolutions of the order of a tenth of a meV are achievable. The effect that various features, such as gap and mirror thickness, lattice mismatches, etc., have on the FPI resonances is studied.

On the Theory of an X-Ray Fabry-Perot Interferometer

“…[18], however, not completely. Firstly, the formulas presented in [18] contain some misprints. Secondly, an essential a-dependence in the phase factor f Eq.…”

“…This leads to different properties of the X-ray FPI. Therefore, the results of computer calculations of the transmissivity obtained in [18] should be revised. It is of interest also to analyze the reflectivity of the X-ray FPI.…”

“…The theoretical treatment of a FPI in the framework of the dynamical theory of X-ray diffraction was performed by Caticha and coauthors in a series of papers [14]± ± [18]. However, up to now the analysis is not complete.…”

“…Especially the influence of imperfections of the FPI mirrors on the performance of the interferometer were not studied. Finally, unfortunately the analysis of the perfect FPI presented in [17,18] contains errors.…”

X-Ray Interferometry with Microelectronvolt Resolution

“…The theory of such devices was propounded by Caticha et al [10,11]. A revised theory taking also into account possible imperfections of the x-ray Fabry-Pérot interferometers was given by Kohn et al [12]; see also [5,13].…”