Apparatus for laser processing and monitoring

A laser processing apparatus comprising:

• a laser beam source;
• a focusing optical system for focusing a laser beam as a processing laser beam to a surface of a to-be-processed article;
• an illuminating optical system using a laser beam of the same frequency as that of the processing laser beam as an illumination laser beam for illuminating the surface of the to-be-processed article;
• a photographing means for detecting the illumination laser beam reflected from the to-be-processed article through the focusing optical system to thereby monitor a processing position by the laser beam;
• a selecting means for selectively shutting one of an optical path of the illumination laser beam passing through the focusing optical system after being reflected at the to-be-processed article to the photographing means for positional monitoring and an optical path of the processing laser beam to the focusing optical system, while maintaining the other optical path;
• and
• wherein the processing laser beam and the illumination laser beam are output from the laser beam source.

A laser processing apparatus comprising:

• a laser beam source;
• a focusing optical system for focusing a laser beam as a processing laser beam to a surface of a to-be-processed article;
• an illuminating optical system using a laser beam of the same frequency as that of the processing laser beam as an illumination laser beam for illuminating the surface of the to-be-processed article;
• a photographing means for detecting the illumination laser beam reflected from the to-be-processed article through the focusing optical system to thereby monitor a processing position by the laser beam;
• wherein the laser beam source has a nonlinear optical crystal as a frequency converting element within a YAG laser oscillator to output a laser beam of second higher harmonics;
• and
• wherein a switching means is provided for switching an optical path of the laser beam of second higher harmonics to that for the illumination laser beam or processing laser beam.