Laser optical system with a single collimating lens and combining means

Abstract

A laser optical system is disclosed which has light source units disposed on a substrate for an assembly incorporating therein a receiving medium such as a photosensitive film. One collimating lens unit and a plurality of semiconductor lasers for emitting laser beams of mutually different wavelengths are attached to the base of the light source unit. The laser beams are superposed one on top of another through the medium of dichroic prisms of dichroic mirrors and the superposed laser beams are caused to impinge on the collimating lens. By fine adjusting units, the laser beams can be moved for fine adjustment in three-dimensional directions. By adjusting the positions of the semiconductor lasers with the finely adjusting means relative to the collimating lens unit, the positions of the optical axes of the laser beams and the diameters of the beams can be easily adjusted. The light source units are movable along the assembly so as to permit easy adjustment of the position at which the superposed laser beams from the light source impinge on the receiving medium.