Method and device for adjusting optical axis of laser light

A device for adjusting an optical axis of laser light, comprising:

• a pair of position sensitive detectors respectively arranged at positions after the laser light has passed through a pair of half mirrors, the pair of half mirrors respectively fixed on an upstream side and a downstream side of a beam expander;
• and
• an adjustment mechanism configured to adjust, based on a position of the laser light detected by each of the position sensitive detectors, at least one of a position and an angle of a pair of movable mirrors that is arranged closer to a laser light source than the pair of half mirrors on an optical path of the laser light, to adjust an optical axis of the laser light.

A method for adjusting an optical axis of laser light, comprising:

• a step of detecting a position of laser light output from a laser light source toward a workpiece, by using position sensitive detectors respectively arranged on an upstream side and a downstream side of a beam expander;
• and
• a step of moving the beam expander to adjust an optical axis of the laser light, based on the position of the laser light detected by the position sensitive detectors in a state where the beam expander is arranged on an optical path of the laser light and the position of the laser light detected by the position sensitive detectors in a state where the beam expander is retracted from the optical path of the laser light.