A device for coupling beam guides of optical systems for unidirectional or bidirectional transmission of beams via a beam transition between the optical systems is provided, the device having a connecting device and mechanical centering means. The connecting device provides a magnetic coupling for implementing a coupling connection in a coupling area. The centering means are situated opposite one another on the optical systems and coupled in such a way to cause the beam guides to self-center due to the attraction caused by the magnetic forces.