provided by an axial cavity 35 in lens 12 in fig1 the protection is provided by the interposition of a metal washer 36 between the tip and the lens length 34 a 34 represents the focal length the device is assembled as follows sleeve 1 equipped with centering device 3 and spring 4 is introduced into base 2 and integrated with this base lens 12 can then be introduced followed by the operation of optimization in which the optical axis of the collimation assembly is made strictly perpendicular to the reference face 18 this operation is carried out with an optimization bench fig1 is a schematic view of an optimization bench for a collimation assembly according to this invention it comprises a coherent laser 40 generating a light beam 41 toward the convex face of a bar lens 42 the laser can be a 10 mw laser generating a signal of 630 nm lens 42 focuses the light beam on the end of an optical fiber 43 which is 300 m in length and has a diameter of 50 125 u03bc this fiber length permits the extinction of the cladding modes the other end of the fiber is molded very precisely inside a standard plug which will be mounted on base 2 of the future optical point the base is integrated with a micromanipulation device 44 by four screws fitting in holes 31 the device is placed on a rigid bench 45 on which are placed facing one another device 44 and a screen 46 at a distance of about 1200 mm the first stage in the optimization operation is the establishment of the target on the.