Polymer optical waveguides can be produced fast and cost-effectively, for example, using flexographic printing. Since the print height in flexographic printing process is usually in the single digit µm range, the resulting cross-sectional area is too small to couple light into the waveguides. Therefore, multiple layers are printed on top of each other to achieve the required waveguide height respectively a sufficient cross-sectional area. This is done sequentially, so that one layer is printed and cured before another layer is applied. There is always a boundary between these different layers, which can have a negative effect on the attenuation of the waveguides. It is therefore desirable to achieve the desired height in as few printing passes as possible.

In this work, it is shown how flexographic printing forms can be modified to increase the height of the transferred material by up to 20% in one printing pass.  To achieve this, different microstructure geometries (hexagon, triangle and square) with different depths are inserted into a printing form. The effect of the structures is investigated by analyzing the printing results. It is shown that depending on the depth and geometry of the microstructures, more or less material can be transferred compared to unstructured areas. To achieve high geometric accuracy and a homogeneous ablation, the microstructures are inserted using a UV nanosecond laser and a mask-based process.