Patent ID: 7352789
Filing Date: 2008-04-01
Classification: B23K,C30B,H01L,H01S

Abstract:
1. A laser light irradiation apparatus comprising: a laser oscillator; a beam expander optical system which laser light oscillated from the laser oscillator enters; and a correction lens disposed between the laser oscillator and the beam expander optical system, wherein the beam expander optical system includes a concave lens, and when an emission point of the laser oscillator is a first conjugate point, a point at which an image at the first conjugate point is formed through the correction lens is a second conjugate point, a distance between the correction lens and the second conjugate point is b, a focal length of the concave lens is f, and a distance between the correction lens and the concave lens is X, the X satisfies b−3|f|≦X≦b+|f|.