X-ray Holographic Microscopy using Total -Reflection Mirror Interferometer

An optical system for X-ray holographic microscopy has been developed using a Fresnel zone plate objective lens and a wavefront-dividing interferometer with total-reflection mirror optics. A plane mirror is placed behind the back focal plane of the objective lens, and half of a divergent wave from the focal point is deflected by the total-reflection mirror and overlapped onto the magnified image of the object. This interferometer is an analogue of a Lloyd's mirror interferometer, which is well known in visible light optics. By using fully coherent illumination to the objective lens, holographic microscopy was successfully performed. A quantitative phase image was obtained by the fringe scan method using a rotating phase shifter. The spatial resolution of the phase image is approximately 200 nm, and the phase sensitivity is estimated to be better than lambda/60 at an X-ray wavelength of 1.0 angstrom. [DOI: 10.1143/JJAP.47.8595]