Comparison of drilling rates and material removal dynamics for nanosecond and femtosecond laser pulses

The results of the interaction of the first harmonic of a 200 femtosecond laser pulse produced by a Ti:Sapphire commercial laser system and the third harmonic of a 40 ns laser pulse produced by a DPSS Nd:YVO4 laser with various materials are reported. The drilling rates were measured as a function of laser pulse energy and material thickness. Differences in material removal rates were observed between the low and high pulse energy. The dependence of the material removal rate on the sample thickness was measured. The observed dependencies of the drilling rate of a femtosecond laser on the laser pulse energy and material thickness are similar to a nanosecond laser drilling. This supports previously suggested hypothesis that a femtosecond laser system produces pulse containing a nanosecond pedestal with estimated energy comparable to the energy of the femtosecond component.