Abstract: The invention relates to the use of the amino groups created on the surface of a polymer material, such as a polypropylene film, by an electric treatment, notably a cold plasma, under nitrogen atmosphere, for accelerating the grafting of the polymer material by impregnating the latter with a bath containing a vinyl type unsaturated monomer comprising a carbonyl group in .alpha. of the double vinyl bond, such as an acrylic monomer.

Abstract: An opto-electronic component such as a semiconductor optical amplifier (L) is mounted on a copper base (EL) which is received in a receptacle constituted by two blocks (DA, DB) of ferrous alloy. Two other blocks (BA, BB) carry fibers to be coupled (FA, FB) and they are fixed to said receptacle by weld spots (PA, QA, PB, QB) on the edges of the faces of said blocks that are bearing against one another. The invention is particularly suitable for optical fiber telecommunications networks.

Abstract: An optical fiber (F) and a laser (L) are fixed on the top faces of two bases (EF, EL) which also have two facing vertical faces. A spring (4) presses these two faces against each other so as to create thrust friction. The thrust force is initially moderate in order to enable the relative vertical and transverse positions (GV, GT) of the two bases to be adjusted smoothly, after which the force is increased progressively in order to prevent relative displacement taking place while the two bases are being welded together by means of a YAG laser. The invention is particularly applicable to making optical transmission heads usable in optical fiber telecommuncations systems.