INFRARED MULTIWAVELENGTH LASER SYSTEM FOR ESTABLISHING A SURGICAL DELIVERY PATH THROUGH WATER

A multiwavelength laser system designed for precise and efficient tiss ue ablation under water was realized by simultaneously coupling radiat ion of a holmium:YAG laser, emitting at a wavelength of 2.12 mu m and an erbium: YSGG laser at 2.79 mu m into the same zirconium fluoride (Z rF4) fiber. The beam paths of the two lasers were collinearly combined taking advantage of the dispersion of an Infrasil prism. Fast video f lash photographs and laser induced pressure transients simultaneously recorded with a PVDF pressure transducer were used to study the dynami cs of bubble formation at the submerged fiber tip. The bubble size and the bubble lifetime were determined as a function of the wavelength a nd the delay time between the two different laser pulses. The results indicate that the combination of 2 and 3 mu m radiation takes specific advantage of both wavelengths and strongly enhances the ablation effi ciency of tissue under water. (C) 1995 American Institute of Physics.