METHOD AND DEVICE FOR ADJUSTING SPOT SIZE OF ONE COLOR COMPONENT OF MULTI-COLOR COAXIAL LASER BEAM

摘要

PROBLEM TO BE SOLVED: To provide a method and a device for changing spot size of a laser spot to which focusing of one color is performed without almost changing the spot size of the laser spot by which focusing is performed on coaxial of the second color. SOLUTION: The method for adjusting the first spot size of the first color component of a multi-color coaxial laser beam includes a step which performs the focusing of the multi-color coaxial laser beam and a step which filters the multi-color coaxial laser beam by using a filter in order to adjust the first spot size. The filter is opaque to the first color component in an annular region of the multi-color coaxial laser beam and transparent to the first color component in the central area. The filter is transparent to the second color component of the multi-color coaxial laser beam in both the central area and the annular region.