Abstract: The device includes a housing, a means for heating the housing, and a means for supporting, in the housing, at least one group composed of plates of malleable material under pressure at the temperature established in the housing. Moreover, the group includes generally flat molds and each mold includes at least one non malleable pitted surface under pressure at said temperature. The molds are inserted between the plates. Means are envisaged to apply a roughly uniform pressure, oriented perpendicularly to the surface of the plates to the entire group. This pressure is suitable for causing the production of convex surfaces of microlenses on the sides of the plates, which are opposite said pitted surfaces of the molds.

Abstract: Preferential etching techniques are used to form a mold which can then be used to mold a microlens array. A mask (4.sub.i) made of a material which is resistant to a chemical composition for etching the plate is formed on a substrate, so that the mask is in the form of a grid with generally polygonal meshes each centered over one of the desired cells. The sides of each cell of the mask has outgrowths (5.sub.j) extending towards the center of desired cells. The substrate is subjected to the etching composition.

Abstract: A plate of a deformable optical material is pressed against a rigid surface furrowed with a congruent network of alveoli by subjecting the two faces of the plate to fluid pressures of different values, the pressure on the face opposite the alveolate surface being less than the pressure on the other face of that plate. The alveoli are deeper than the thickness of the convex part of the microlenses formed therein by permanent deformation of the plate under the applied pressure.