Focus control system for laser welding.

@article{Haran1997FocusCS,
  title={Focus control system for laser welding.},
  author={F M Haran and Duncan P. Hand and Charles Peters and Julian D C Jones},
  journal={Applied optics},
  year={1997},
  volume={36 21},
  pages={5246-51}
}
We describe a focus control system for Nd:YAG laser welding based on an optical sensor incorporated into the fiber delivery system to detect light generated by the process. This broadband light is separated into two wavelength bands, and simple electronic processing gives a signal proportional to focal error as a result of chromatic aberrations in the optical delivery system. Focus control is demonstrated for bead-on-plate welds in different thicknesses of titanium alloy, aluminum alloy, mild… CONTINUE READING