A beam shaping optical arrangement combines three incoming laser beams that are mutually laterally offset in two orthogonal directions (X and Y), including an incoming first central laser beam and second and third incoming beams laterally offset in the X direction on either side of the central beam, into one outgoing combined laser beam. The arrangement includes two lateral displacement optical units though which the laterally offset incoming beams are transmitted and that laterally displace the two laterally offset incoming beams along the X direction towards the incoming central beam but which do not laterally offset the incoming central beam. The lateral displacement units include a material having a higher refractive index than a medium located in an optical path of the central laser beam, and the optical path length traversed by the incoming laterally offset laser beams is selected such that, after transmission though the optical units, the diameters of the central laser beam and the laterally offset laser beams are approximately equal at least in the X direction, and a divergence of the central laser beam is approximately equal to a divergence of the laterally offset laser beams.