Submicrometer resolution hard X-ray holography with the asymmetric bragg diffraction microscope.

The asymmetric Bragg diffraction microscope is a novel x-ray microscope which forms a magnified in-line near-field hologram by asymmetric reflection from two crossed flat crystals. In this paper, the optics of the microscope is studied theoretically. The optical transfer function is obtained, and the limiting spatial resolution, rated at 25% modulation transfer, is determined to be 0.30 microm at an optimum magnification of 89x with Si crystals, over a wide range of hard x-ray wavelengths. Absorption and phase contrast images can be computed from holograms acquired at several object distances. Application to submicrometer resolution hard x-ray microtomography is envisioned.