Laser process monitoring with dual wavelength optical sensors Available to Purchase

Manufacturing is becoming increasingly concerned with quality control and the potential for in-process monitoring has, in consequence, become one of growing value. It is particularly easy to gain meaningful signals during laser processing due to the nature of optical energy (1,2). Considered here are the preliminary results of studies in which the radiation emitted from the laser interaction zone is analysed at two wavelength bands. The radiation coming from this zone is considered to have two basic sources. The hot material which will radiate mainly in the infrared, at temperatures up to its boiling point and the plasma which will radiate mainly in the ultraviolet, at temperatures up to 10⁴ °K both sources having an intensity versus wavelength distribution described by Planck’slaw. Comparison between the two signals reveals considerable data on the quality of a weld or cut while it is being made.