Transmission of high erbium: YAG laser pulse energies through germanium oxide trunk fibers with sapphire tips

Travis J. Polletto, Anthony K. Ngo, Alexei Tchapyjnikov, Ken Levin, Danh Tran, Nathaniel M. Fried

Research output: Chapter in Book/Report/Conference proceedingConference contribution


Endoscopic applications of the Erbium:YAG laser have been limited due to the lack of a suitable optical fiber delivery system. This study compares the transmission of Er:YAG laser radiation through germanium oxide trunk fibers with silica or sapphire fiber tips for potential use in endoscopic tissue ablation. Er: YAG laser radiation with a wavelength of 2.94 μm, pulse length of 300 μs, pulse energies of 5-1360 mJ, and pulse rates of 3-10 Hz, was delivered through 1-m-long germanium oxide fibers with either 1-cm-long, 550-jjm-diameter silica or sapphire tips. Transmission through the germanium oxide / sapphire fibers measured 65 ± 5 % compared with 55 ± 4 % for the germanium oxide / silica fibers (P <0.05). The damage threshold for the hybrid fibers averaged 309 ± 44 mJ and 126 ± 43 mJ, respectively (n = 7 fibers each) (P <0.05). Maximum pulse energies transmitted through the fibers were 700 mJ and 220 mJ, respectively. Improved index-matching of the trunk fiber and fiber tip at 2.94 μm resulted in higher transmission and damage thresholds for the germanium oxide / sapphire fibers. The germanium oxide / sapphire fiber may represent a promising mid-IR optical fiber delivery system for use in endoscopic applications of the Er:YAG laser requiring a flexible, biocompatible, and robust fiber delivery system for contact tissue ablation.

Original languageEnglish (US)
Title of host publicationProgress in Biomedical Optics and Imaging - Proceedings of SPIE
StatePublished - 2007
EventPhotonic Therapeutics and Diagnostics III - San Jose, CA, United States
Duration: Jan 20 2007Jan 21 2007


OtherPhotonic Therapeutics and Diagnostics III
Country/TerritoryUnited States
CitySan Jose, CA


  • Endoscopic
  • Er:YAG
  • Erbium
  • Erbium:YAG
  • Germanium oxide
  • Mid-infrared

ASJC Scopus subject areas

  • General Engineering


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