Polycapillary Optics (PO)

Polycapillary optics are arrays of small hollow fibers. X-rays are guided down these curved and tapered tubes by multiple reflections in a manner analogous to the way fiber optics guide light. They differ from single-bore capillaries and X ray mirrors in that the focusing or collecting effects come from the overlap of the beams from thousands of channels, rather than from a few surfaces.

Generally, this results in relatively efficient collection, especially from large divergent sources such as conventional X ray tubes,but does not produce submicron beam spot sizes.