DEVICE AND METHOD OF LASER BEAM MACHINING FOR TRANSPARENT HARD BRITTLE MATERIAL

摘要

PROBLEM TO BE SOLVED: To provide a device and method of laser beam machining for a transparent hard brittle material, using thermal stress produced by laser beam irradiation, the device and method that are capable of suppressing waviness in a cut section in case of using a highly absorptive laser beam and that are capable of improving workability in the case of using a highly transmissive laser beam. SOLUTION: A semi-transparent mirror 6 and a reflection mirror 7 are installed in a manner of holding a transparent hard brittle material in between 4 which is an object to be machined. The semi-transparent mirror 6 is one that totally reflects a laser beam 2 from the side of the transparent hard brittle material 4 and that transmits the laser beam from the opposite side, while the reflection mirror 7 is one that totally reflects the laser beam 2. Machining is performed by transmitting the laser beam 2 through the transparent hard brittle material 4 while the laser beam is repeatedly reflected between the semi-transparent mirror 6 and the reflection mirror 7.