Figure 7
Normalized intensity of the focal spots created by two stacked zone-doubled FZPs with an outermost zone width of [\Delta r] = 25 nm. (a) With two FZPs of identical diameter, D = 45 µm, the focal spot is distorted by increasing their separation distance, ld. (b) For a chosen separation distance of ld = 25 µm, the optimal focal spot is recovered when the diameter of the second FZP is adjusted to D2 = 44.8 µm.  [article HTML]