An Er:YAG laser light delivery system composed of a polymer-coated silver hollow waveguide and a quartz sealing cap has been developed for calculus fragmentation. Sealing caps with various distal-end geometries were fabricated, and the focusing effects of these caps for Er:YAG laser light were measured both in air and in water. Owing to the high power capability of the quartz sealing caps, a beam of Er:YAG laser light with an output energy of 200 mJ and a repetition rate of 10 Hz was successfully transmitted in saline solution by use of the system. Calculus fragmentation experiments conducted <i>in vitro</i> showed that the delivery system is suitable for medical applications in lithotripsy. We also found that the cap with a focusing effect is more effective in cutting calculi. The deterioration of the sealing caps after calculus fragmentation is also discussed.
© 2003 Optical Society of America
(140.3070) Lasers and laser optics : Infrared and far-infrared lasers
(160.5470) Materials : Polymers
(170.1610) Medical optics and biotechnology : Clinical applications
(170.7230) Medical optics and biotechnology : Urology
(230.7370) Optical devices : Waveguides
Katsumasa Iwai, Yi-Wei Shi, Koh Nito, Yuji Matsuura, Takao Kasai, Mitsunobu Miyagi, Seichi Saito, Youichi Arai, Naomasa Ioritani, Yoshihide Okagami, Michal Nemec, Jan Sulc, Helena Jelinkova, Miroslav Zavoral, Oto Kohler, and Pavel Drlik, "Erbium:YAG Laser Lithotripsy by Use of a Flexible Hollow Waveguide with an End-Scaling Cap," Appl. Opt. 42, 2431-2435 (2003)