Optical techniques for real-time penetration monitoring for laser welding

Fabrice Bardin, Adolfo Cobo, Jose M. Lopez-Higuera, Olivier Collin, Pascal Aubry, Thierry Dubois, Mats Högström, Per Nylen, Peter Jonsson, J. D C Jones, Duncan P. Hand

Research output: Contribution to journalArticlepeer-review

55 Citations (Scopus)


Optical techniques for real-time full-penetration monitoring for Nd:YAG laser welding have been investigated. Coaxial light emission from the keyhole is imaged onto three photodiodes and a camera. We describe the spectral and statistical analyses from photodiode signals, which indicate the presence of a full penetration. Two image processing techniques based on the keyhole shape recognition and the keyhole image intensity profile along the welding path are presented. An intensity ratio parameter is used to determine the extent of opening at the rear of a fully opened keyhole. We show that this parameter clearly interprets a hole in formation or a lack of penetration when welding is performed on workpieces with variable thicknesses at constant laser power. © 2005 Optical Society of America.

Original languageEnglish
Pages (from-to)3869-3876
Number of pages8
JournalApplied Optics
Issue number19
Publication statusPublished - 1 Jul 2005


Dive into the research topics of 'Optical techniques for real-time penetration monitoring for laser welding'. Together they form a unique fingerprint.

Cite this