Acoustic cavitation events during microsecond irradiation of aqueous solutions

The acoustic boundary conditions at the site of laser irradiation a®ects the onset of cavitation when stress-con¯ned laser pulses are used. This study reports the thresholds for cavitation when the laser pulse length exceeds the stress con¯nement time by a factor of eight. The cavitation threshold was de¯ned as the loss of an acoustic signal from the collapse of the cavitation bubble in room temperature dye solutions. The threshold temperature increase for cavitation at a free surface was 13§3±C, at the tip of a 200m ¯ber in an aqueous solution was 17§2±C, and at the interface of two acoustically matched boundary materials was 80§20±C