Precise determination of the focal point on a glass sample using spectroscopy analysis

摘要

Laser marking of various materials is commonly used nowadays in commercial products. In the past two decades, CO2 lasers have been used extensively to mark insulators such as glass and wood during industrial production. Usually, a system of mirrors is used during a marking procedure. Although a laser beam can be characterized accurately using well-known methods, it is desirable to identify where the focal point is after reflecting on the scanning mirrors. The positioning of a motorized stage with a knife-edge and a sensing device to characterize a beam after reflecting through a mirror scanner system is impractical due to limited space. The method described here to determine the focal point accurately requires using only a large numerical aperture fiber connected to a motorized stage. In this paper, we investigate how spectroscopy of typical emission lines can be used to identify the position of the focal point in real time during laser marking procedures. (C) 2021 Optical Society of America