Abstract
High-aspect-ratio microdrilling of borosilicate glass has been demonstrated by the forth harmonic of nanosecond Nd:YVO4 laser. In this paper, we investigated about the influence of the pulse width on the hole profile. The pulse width was expanded by splitting the laser beam and mixing after passing through optical passes with different length. Firstly, the holes drilled with various polarized beam. As a result, depths of the holes drilled with different polarization of the beam were same. Then depths of the drilled holes with different pulse width were measured. Deeper holes were obtained with faster pulses when the deep holes were drilled. However, no clear difference was observed when the drilled holes were shallow. The profiles of the holes drilled with different pulse width were measured. As a result, the profiles were almost same around the entrance. On the other hand, the diameters of the holes drilled with slower pulses were a few μm smaller than that with faster pulses around the bottom. It was shown that pulse width influenced more when deep holes were drilled.
