Figure 4: Free-form optical elements: Donut and top hat shaper.
From: Sub-micrometre accurate free-form optics by three-dimensional printing on single-mode fibres
(a) Illustration of a donut shaping free-form lens. The lens design is calculated by an iterative optimization algorithm using Huygens–Fresnel principle. (b) Intensity distribution of a donut-shaped beam profile with cross sections in x- and y-direction. In addition, the backward calculation that has been determined from the measurement is shown. (c) Microscope image of the side view of the top hat shaping free-form optical element with indicated designed surface and the surface based on backward calculation out of the measurement results. The white vertical lines indicate the beam width. (d) Intensity distribution of a top hat-shaped beam profile with cross-sections in x- and y-direction. In addition, the backward calculation that has been determined from the measurement is shown.
