Improved hole drilling using a high peak power Nd:YAG laser at the second harmonic wavelength

We have previously described the drilling of advanced materials such as intermetallics, superalloys, and composites using an Nd:YAG laser operating at the fundamental wavelength of 1.06 mu m [1]. We have now extended these studies to the second harmonic wavelength of 532 nm of a high peak power Nd:YAC laser. The results show that drilling using the shorter wavelength further reduces undesired thermal effects such as recast layers and heat affected zones. A comparison of these results with those obtained at the fundamental wavelength is reported.