PRESSURE IMPULSES DURING MICROSECOND LASER-ABLATION

The collapse of laser-induced cavitation bubbles creates acoustic tran sients within the surrounding medium and also pressure impulses to the ablation target and light-delivery fiber during microsecond laser abl ation. The impulses are investigated here with time-resolved flash pho tography, and they are found to occur whether or not the light-deliver y fiber is in contact with the target. the impulses depend primarily o n the energy stored in the cavitation bubble. dependent on the mode of light delivery (contact versus noncontact), and they are also not dir ectly correlated to the other acoustic transients. The pressure impuls es do seem to be associated with the bubble-driven jet formation cause d by the bubble collapse. (C) 1997 Optical Society of America.