LASER DRILLING METHOD AND SYSTEM FOR PRODUCING SHAPED HOLES

摘要

A laser-based drilling system and process for producing shaped holes in a workpiece includes a high power fiber laser assembly including a passive fiber with a non-circular core and configured to emit a plurality of light pulses each with a Gaussian distribution of electromagnetic. The pulses each are emitted at such a wavelength, repetition rate and having a rater duration that as the beam penetrates through the workpiece a region of the near field of the Gaussian beam forms a diffuser portion of the shaped hole and the far field of the beam forms a metering hole portion. The diffuser portion extends between the entrance surface and the waist of the Gaussian beam and has an orifice on the entrance surface having a contour substantially repeating the non-circular shape of the core. The shaped holes can be produced in one shot in a range varying between about of 5 and 15 milliseconds at high repartition rate of up to 100 holes per second.