In this paper speckle correlation is introduced as a tool to investigate the heat-influenced area during material processing with laser light. Two materials were investigated, a pure silver sheet and a sheet of SiC–diamond composite. The processing laser used in the experiments was a diode-pumped acousto-optical <i>Q</i>-switched Nd:YAG laser that allowed percussion hole drilling to be performed using green light through a second-harmonic crystal. The measurements were performed using a continuous-wave He–Ne laser and a digital camera. The experimental results show that the heat-influenced area is ∼5000 times larger than the actual hole being drilled and that it reaches a steady-state condition toward the end of the processing cycle.
© 2005 Optical Society of America
(120.0120) Instrumentation, measurement, and metrology : Instrumentation, measurement, and metrology
(120.6160) Instrumentation, measurement, and metrology : Speckle interferometry
(350.3390) Other areas of optics : Laser materials processing
Instrumentation, Measurement, and Metrology
O. Yalukova, N. Miroshnikova, P. Gren, I. Sárady, and M. Sjödahl, "Investigation of laser percussion hole drilling by use of speckle correlation," Appl. Opt. 44, 6338-6344 (2005)