LASER OSCILLATOR

摘要

PROBLEM TO BE SOLVED: To provide a laser oscillator which controls a laser beam to keep the laser beam diameter always constant regardless machining spot. SOLUTION: The oscillator is provided with mirror driving devices 3A and 3B which collimate the laser beam by varying the distance between a convex mirror 2A and a concave mirror 2B installed in the transmitting path of the laser beam 4 and varying an angle of each of the mirrors, a beam diameter setting means 11 for preliminarily setting the laser beam diameter before the laser beam is collimated, and a controller 5 which controls the mirror driving devices 3A and 3B so that the laser beam diameter is kept constant at the machining spot even the position of the machining spot moves by calculating the distance and the angle with a correction coefficient corresponding to the optical path from the exit of the laser oscillator to the machining spot on the basis of the set laser beam diameter.