Physical phenomena produced by Ho-YAG laser in endourology

The high temperatures generated by the holmium laser pulses during endourological treatments have been reported, the physical phenomena related to this event has never been interpreted. During our clinical experience we had some steel wires sheared by the holmium pulses (fig. 1), after microscopic analysis we considered that only the plasma was able to cause those damages. The aim of this work was to understand the phenomena produced by the holmium laser pulses through measurements of temperature around the fiber tips, we determined the plasma formation thresholds for each fiber types, and also the plasma bubble dimensions.