| 摘要 |
PROBLEM TO BE SOLVED: To easily and efficiently obtain light formed to a beam shape of a ring band form. SOLUTION: The laser beam emitted from a UV solid-state laser 2 is made incident on a biaxial double refracting crystal 14. The laser beam is formed to the beam shape of the ring band form by this biaxial double refracting crystal 14 and is condensed to a semiconductor wafer 30 by an objective lens 17. Namely, the optical system utilizing apodization is embodied by a nonlinear optical crystal (biaxial double refracting crystal 14) having biaxial double refractions. |
