| 摘要 |
Disclosed is a laser irradiation apparatus to be used in laser processing. A laser processing method using the laser irradiation apparatus is also disclosed. The laser irradiation apparatus is provided with a light source, which emits laser beams, and an irradiation optical system, which has one or a plurality of lenses and guides and collects the laser beams emitted from the light source to a subject. The laser irradiation apparatus and the laser processing method are characterized in that a birefringent material is used as a material for at least one lens of the irradiation optical system. The irradiation optical system has a first lens, i.e., a concave lens or a convex lens, and a second lens, i.e., a convex lens, in this order in the laser beam traveling direction, includes a beam expander wherein the interval between the first lens and the second lens is variably configured, and as a material for the first lens and/or the second lens, the birefringent material is preferably used. |
