Abstract: The subject of the invention is a laser comprising a semiconductor active medium with a population inversion lifetime ?c and a resonant cavity with a lifetime of the photons in the cavity ?p. The cavity includes means for being longitudinally monomode and means so that ?p>?c, such as for example a very long cavity, so as to obtain a laser with a very low intrinsic noise.

Abstract: A coupler comprising a photodiode having a central passage and fitted on the end portion of a first optical fiber which is rigidly fixed to a casing, a second optical fiber being rigidly fixed to a sleeve slidably fitted within the casing and having an end-face located at an adjustable distance from an end-face of the first optical fiber and from the photodiode in order to adjust the light-energy extraction rate to a predetermined value, and comprising means for adjusting the spacing between fibers.

Abstract: The invention relates to a manual and portable device for crimping ferrules onto bundles of optical fibres comprising a number of fibres such that these fibres may be hexagonally arranged. The device primarily comprises means for holding the ferrule in the tool, crimping means essentially consisting of an element supporting three knurled rollers which is capable of being rotated whilst the three knurled rollers, at the same time as rotating, may be moved progressively nearer the axis of the bundle until their spacing corresponds to the minimum cross-section of the bundle. The device may also comprise a release mechanism enabling the approach movement of the knurled rollers to be stopped when this cross-section is reached.

Abstract: The invention provides a substrate for positioning the end of one or more optical fibres in a reference plane. Each fibre is positioned by means of three right circular cylindrical dowels in a staggered arrangement on the flat trued face of a parallelepiped. The substrate may further comprise a single additional optical fibre bearing against the apertures of the transmission fibres and doing duty as a cylindrical lens for coupling each transmission fibre with the emissive zone of a laser diode.