LASER IRRADIATION APPARATUS

摘要

PROBLEM TO BE SOLVED: To provide a laser irradiation apparatus which can uniformly irradiate an object for irradiation with a laser beam without generating the interference fringes by diffracted light and reflected light at joined surfaces even if a laser beam source having high coherence is used.

SOLUTION: The laser irradiation apparatus irradiates the object for irradiation with the laser beam 1 by deforming the laser beam from a circular sectional shape to a rectilinear sectional shape. The laser irradiation apparatus is provided with the laser beam source 12 for emitting the laser beam 1a of the circular shape, a lens system 14 for deforming the laser beam to the rectilinear shape, a homogeneizer 16 for homogeneizing the intensity distribution of the laser beam 1b, and an interference reducer 20 disposed between the homogeneizer and the lens system to reduce the interference effect of the laser beam. The interference reducer 20 comprises an optical path correction lens 22 consisting of a plurality of transparent glass plates 22a made successively longer by the prescribed length X longer than the coherent length and a photomask 21 for shielding the laser beam made incident on the boundary of the optical path correction lens 22.

COPYRIGHT: (C)2004,JPO