We report a first approach for the structuring of mold insert to obtain antireflective optical surfaces. We present the results of 2D finite element simulations made with COMSOL software, to define theoretically the shape and dimensions of the structuration to achieve. On the basis of these calculations indicating that the structuration must have triangular shape elements in contact with each other, we described a technological approach which uses a monolayer of hexagonal closed packed spherical particles (colloidal crystal) as sacrificial mask associated with plasma etching. The mold insert prototyped in a Diamond Like Carbon (DLC) material with the technique developed, presented pyramidal elements as expected. However, optical analysis of the first molding made with a silicone material show no increase in the transmission spectra. This result is probably due to a difference between the shape and organization of the structuration performed and the theory.