Figure 6
The intensity profile in the vicinity of the focus as a function of the propagation distance z1F for the aperture sizes [\Omega_{\rm{A}}] of 25 µm (a), 100 µm (c) in the horizontal direction. The white dashed lines indicate the coherent part of the beam with a width given by the transverse coherence length. (b), (d) Line scans of the intensity profile I(x) from (a), (c) in the focal plane at z1F = 0. The shaded region shows the coherent part of the beam with the width corresponding to the transverse coherence length [\xi_{\rm{F}}] in the focal plane.  [article HTML]