High-power CO 2 blending-mode laser beam propagation and focus due to phase shifts

Abstract

In laser materials processing, the transverse intensity distribution of focus affects processing quality greatly. In this paper, phase shifts is used to analyze high-power CO<SUB>2</SUB> laser beam propagation and focus, especially the change of transverse intensity distribution along beam propagation path. From theory, the phase shifts of high-power blending laser beam determines the transverse intensity distribution. It is also found that if there contains odd mode in blending laser beam, the asymmetry of laser beam is broken. Moreover the high-power laser beam focus and unfocused diagnosis system UFF100 is used to test the beam transverse intensity distribution. Theory is accord with measurement. According to the theory, two optical transformation system is designed to attain the minimum intensity changes.