Method and apparatus for drilling watch jewels or other workpieces by means of laser beams

A method for drilling holes in workpieces which are highly transparent or highly reflective to laser light, said method comprising applying a single laser pulse to the workpiece, forming the laser pulse with a plurality of spikes, the intensity of the first of these spikes being greater than that of all subsequent spikes and said subsequent spikes follow each other with a substantially constant period, providing the first spike with an intensity sufficient to vaporize a surface layer of the material of the workpiece, providing the subsequent spikes with sufficient energy such that each vaporizes a layer of material having a thickness of approximately 20 .mu.m so as to form a hole in the workpiece, and maintaining the period between said subsequent spikes sufficiently large such that the vaporized material produced by a previous spike has escaped from the hole being formed before the next spike arrives at the workpiece, said spikes having an energy of approximately 1 m Joule, the duration of the spikes being approximately 0.5 .mu.sec, the period between the spikes being approximately 3 .mu.sec and the peak intensity being less than 10.sup.9 W/cm2.