Fig. 2.

Examples of point spread functions in three EDoF systems: Our method (a,d); the cubic phase method (b,e); and the liquid slab method(c,f). From top to bottom, the distance to the focal plane is 0, 60 $\mu m$ respectively. The PSFs are plotted off center to accommodate the shape of PSFs from the cubic phase mask method. The Strehl ratio (Log scale) vs. axial distance of these three methods is plotted in (g).