Abstract: Connection device for multiple-core optical fibers based on optical elements in free space. This device comprises a first optical means (36) which is refractive or diffractive, and at least one second means (38, 40) which is diffractive. The first means causes the light beams exiting cores (30) of fiber (28) to diverge as far as an area in which these beams are separated in space and have cross sections whose size is compatible with the spatial bandpass of the second means. The latter is positioned in this area and directs the beams, independently from one another, towards corresponding optical components (34). Application to optic telecommunications.