RESUMEN
We propose what we believe to be a new kind of diffractive phase element, i.e., vortex phase plate (VPP) with phase singularities along the azimuth direction. Phase function of the proposed VPP is given analytically. Axial intensity oscillations of propagating Bessel beams are ideally suppressed by using the proposed VPP. Compared with the traditional amplitude mask, the proposed VPP takes such advantages as a simpler fabrication procedure and a lower cost.
RESUMEN
Neutron imaging is an invaluable tool for noninvasive analysis in many fields. However, neutron facilities are expensive and inconvenient to access, while portable sources are not strong enough to form even a static image within an acceptable time frame using traditional neutron imaging. Here we demonstrate a new scheme for single-pixel neutron imaging of real objects, with spatial and spectral resolutions of 100 µm and 0.4% at 1 Å, respectively. Low illumination down to 1000 neutron counts per frame pattern was achieved. The experimental setup is simple, inexpensive, and especially suitable for low intensity portable sources, which should greatly benefit applications in biology, material science, and industry.