We discuss the possibility of a new interference technique for x-ray and γ-ray optics—the simple idea of grazing-incidence antireflection films (GIAR films)—for creating high-efficiency antireflection coatings for near-grazing-incidence reflection of hard x rays and γ rays. The motivation is the possible application to producing ‘‘ultranarrow’’ bandpass filters for synchrotron radiation with frequency widths ≊${10}^{\mathrm{-}8}$–${10}^{\mathrm{-}6}$ eV, giving a unique high-resolution, long-coherence-length, x-ray source for probing soft inelastic excitations and opening up new possibilities in x-ray interferometry. In this first of two papers on nonresonant GIAR films, we develop the basic theory and discuss in detail the simplest ideas for achieving antireflection films—impedance-matched quarter-wave films and damping stabilized solutions—which can both be obtained by coating a high-density mirror with a single lower-density film.

• Received 9 May 1984

DOI:https://doi.org/10.1103/PhysRevB.32.5068