Beam homogenizer and laser irradiation apparatus

摘要

Since the arrangement of the optical elements in the optical system is limited because of their characteristic, designing the optical system for forming the desired laser beam is difficult. An object of the present invention is to design the optical system having the desired function without being affected by the limit in the arrangement of the optical elements. Consequently, an off-axis cylindrical lens array is used as a cylindrical lens array acting on a long-side direction of the beam.