Abstract: Optical fibre coupler comprising at least three branches of the optical fibre type. A three-branch coupler comprises first and second optical fibres having two end frustoconical portions which are fastened to one another. The two frustoconical portions are terminated by a first common spheroidal end centered on their common generatrix and having a diameter substantially greater than the sum of the core diameters of their small end bases. The third branch of the three-branch coupler is constituted by a third optical fibre whose end lies opposite the first spheroidal end. In the case of a four-branch coupler, the fourth branch is constituted by a fourth optical fibre. The ends of the third and fourth optical fibres are formed as two frustoconical portions which are fastened to one another and terminated by a second common spheroidal end analogous to the first spheroidal end. The first and second spheroidal ends lie opposite each other.