Publications

An Alternative Form of Laser Beam Characterization

Knorovsky, Gerald A.; Maccallum, Danny O.

Careful characterization of laser beams used in materials processing such as welding and drilling is necessary to obtain robust, reproducible processes and products. Recently, equipment and techniques have become available which make it possible to rapidly and conveniently characterize the size, shape, mode structure, beam quality (Mz), and intensity of a laser beam (incident power/unit area) as a function of distance along the beam path. This facilitates obtaining a desired focused spot size and also locating its position. However, for a given position along the beam axis, these devices typically measure where the beam intensity level has been reduced to I/ez of maximum intensity at that position to determine the beam size. While giving an intuitive indication of the beam shape since the maximum intensity of the beam varies greatly, the contour so determined is not an iso-contour of any parameter related to the beam intensity or power. In this work we shall discuss an alternative beam shape formulation where the same measured information is plotted as contour intervals of intensity.