X-ray Phase Laminography with Talbot Interferometer

Laminography is a technique for 3D volume reconstruction, extending the classical tomography to the estimation of local areas in lamellar objects. We demonstrate X-ray phase laminography by using an X-ray Talbot interferometer consisting of two transmission gratings, which has been used only for X-ray phase tomography. In this presentation, experiments using 17.7 keV synchrotron radiation through a double-crystal monochromator are reported. The X-rays passed through the sample placed in front of the first phase grating. The rotation axis of the sample was set almost parallel to the sample plane normal, and inclined from the X-ray beam. Behind the second amplitude grating, moire fringe patterns were measured by displacing one of the gratings in the direction parallel to its diffraction vector. Differential phase information were extracted through the fringe-scanning method. For the reconstruction of the three-dimensional volume from the differential phase information, the filtered back projection method was used with a specific filtering function. Promising results of phase laminography reconstruction are obtained for simulation data as well as weakly absorbing lamellar objects such as a polymer meshes and other samples. This advancement extends experiments with X-ray Talbot volume reconstruction to a larger variety of samples.