Abstract: The present invention relates to the field of patterning substrates with periodic dot structures in the micro- or sub-micrometer range, in particular to an apparatus and a method for structuring surfaces and the interior of a transparent substrate by means of laser interference structuring. The pattern produced in this way with periodic dot structures in the micro- or sub-micrometer range is characterized by a pronounced anti-reflective property. In addition, the present invention relates to a patterned substrate with anti-reflective properties comprising a periodic dot structure.