| 摘要 |
PROBLEM TO BE SOLVED: To provide a laser beam irradiation device for use in laser beam machining and a laser beam machining method using the same.SOLUTION: The laser beam irradiation device comprises a light source for outputting laser beams and an irradiation optical system that has one or more lenses and allows laser beams output from the light source to be guided to and focused on an object. A birefringence material is used as a material for at least one of the lenses in the irradiation optical system. The laser beam irradiation device is used in the laser beam machining method. Preferably, the irradiation optical system comprises a first lens, which is a concave lens or a convex lens, and a second lens, which is a convex lens, provided in that order in the direction of travel of laser beams and further comprises a beam expander configured to vary spacing between the first and second lenses, and the first lens and/or the second lens are formed of a birefringence material. |
