Table 1. Design parameters of the three types of kinoform lenses measured, consisting of a single-element lens and compound lenses consisting of arrays of five and ten lenses.

Increasing the number of lenses allows for larger apertures and improved resolution but comes at the price of insertion loss.

Lens type	Number of lenses in array	Individual lens focal length (m)	Aperture (mm)	Phase-shifts per lens element	Transmission of compound lens	Resolution of compound lens (nm)
Short	1	0.7	0.315	16π	0.84	250
Medium	5	3.5	0.780	8π	0.43	102
Long	10	7	1.1	8π	0.18	73