Beam-steered Nd:YAG lasers ("YAG") at 1064nm wavelength (near infrared spectrum) are popular in the laser marking industry due to their emission wavelength, power performance and versatility. This results in faster marking speeds, higher quality and greater production. As reference, the continuous wave (CW) CO2 lasers operate at a wavelength of 10.6 µm (far infrared spectrum). CW CO2 lasers generate comparatively much lower peak power and normally cannot produce high contrast markings on many plastics.
The mechanism of laser marking is to irradiate the polymer with a localized high-energy radiation source (laser). The radiant energy is then absorbed by the material and converted to thermal energy. The thermal energy induces reactions to occur in the material. Beam-steered YAG laser markers (arc lamp & diode light pumping sources) utilize mirrors that are mounted on high speed computer controlled galvanometers to direct the laser beam across the surface to be marked. Each galvanometer, one on the Y-axis and one on the X-axis provides the beam motion within the marking field.