Multilevel stacked Fresnel zone plate for hard x-rays

Stacking technique of the Fresnel zone plate fabrication with effective multilevel zone structure was considered by means of numerical simulation. It was shown that such approach allows increasing focusing efficiency without essential additional fabrication difficulties since the proposed device is a simple combination of bi-level structures. The conditions, at which layers are acting as a single zone plate, as well as criteria of layer alignment aren’t significantly changed compared with those of bi-level case. The angular sensitivity estimation shows that it allows imaging of objects larger than zone plate diameter.