Apparatus for drilling a via-hole in a printed circuit board (PCB) includes a carbon monoxide laser deliver laser radiation pulses. The pulses have a relatively broad wavelength-range, and slow rising and falling edges. The rising and falling edges of the pulses are clipped using and acousto-optic modulator. A dispersion-compensator compensates for dispersion in the clipped pulses introduced by the AOM. Achromatic focusing optics focus the dispersion-compensated, clipped pulses on the PCB for the via-hole drilling.