Figure 6
(Upper left and lower left) Horizontal and vertical slices through the reconstructed focal intensity (Dataset 3). In contrast to Datasets 1 and 2 here a smaller pinhole (diameter = 1.4 µm) has been used which significantly influences the focal intensity distribution. Here the beam-defining slits S1H and S1V were set to 0.1 mm. Graphs are analogous to those of Fig. 4 . (Upper right and lower right) Even though in the numerically determined focal plane a double-focus is visible, the small pinhole P2 drastically reduces the side lobes in the focal plane. After further propagation to ∼1.6 mm downstream of the reconstruction plane the wavefield becomes a single focus in the horizontal and vertical directions and adopts almost a Gaussian shape (see Fig. 7 ). |