Observation of the Talbot Effect at Beamline 6C Bio Medical Imaging of the Pohang Light Source-II

The Talbot effect is used in novel contrast imaging techniques that measure X-ray refractions and scattering. We examined formation of periodic fringes by the Talbot effect at beamline 6C Bio Medical Imaging of the Pohang Light Source-II, a facility for synchrotron radiation X-ray imaging. Talbot fringes were not observable under a normal illumination condition at the beamline, but appeared when we made a narrow opening of a slit next to the synchrotron radiation source that should have improved the transverse coherency of the beam. The Talbot fringes were identified by comparison with a numerical simulation, and also measuring the fringe visibility at fractional Talbot distances using grating interferometry.