Etch rates (μm/pulse) for glycol-modified polyethylene terephthalate (PETG) under pulsed UV (255 nm) laser processing are measured as a function of pulse repetition frequency in the range 0.7-15 kHz. Materials removal rates (μm/s) scale approximately linearly with pulse repetition frequency at a fluence of 0.59 J/cm2, and there appears to be no attenuation of the ablating laser beam by the ejected material plume for pulse rates up to 15 kHz. The instantaneous etch rate for pulses in a sequence increases markedly (approx. 40%) for long pulse sequences (>100 pulses) at high PRF (15 kHz), an effect which can be used to increase machining rates while operating at a moderate laser fluence.
|Number of pages||6|
|Journal||IEEE Journal on Selected Topics in Quantum Electronics|
|Publication status||Published - Nov 1999|
- laser ablation
- laser machining
- pulsed lasers