METHOD AND DEVICE FOR PROCESSING INSIDE OF TRANSPARENT MATERIAL

摘要

A shape with a substantially perfect circle is obtained as a processed shape such as a modified shape or a worked shape at a light focus point in a cross-section in a direction parallel to an advance direction of a femtosecond laser light beam. A section in a direction perpendicular to an advance direction of a laser light beam emitted from a femtosecond laser (10) is formed in a predetermined shaped. The laser light of which sectional shape in the direction perpendicular to the advance direction is formed in the predetermined shape is entered into a lens (14). The light is focused by the lens inside a transparent material (100) and processes the inside of the transparent material.