Abstract
A new optical system for controlling spatial profile of laser beam has been developed. The principle of the system controls independently transverse and longitudinal diameters of the laser beam. The system consists of cylindrical mirrors and integration mirrors which focus the beam in directions perpendicularly intersecting with each other. In order to investigate the focusing property of the optical system, a calculating model for predicting beam paths through the optical system has beendeveloped using the ray tracing method. According to the model, three typical optical systems for a line shape focused beam have been designed-(1), two cylindrical mirrors, (2) one cylindrical mirror and one integration mirror, and (3) one cylindrical mirror and one integration mirror with convex segments. After laser heating experiments of steel by using these optical systems, it has been proved that they are useful in actual industrial applications.