Transmission of free-running and Q-switched Er: YAG and Er:YSGG laser energy through germanium oxide/silica fibers

Nathaniel M. Fried, Yubing Yang, Kyunhee Lee, Hussain A. Tafti

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

9 Scopus citations


Endoscopic Erbium laser applications have been limited by the lack of a suitable optical fiber. This study describes a hybrid germanium oxide/silica fiber for transmission of Q-switched and free-running Er:YAG and Er:YSGG laser radiation. Hybrid fibers consisted of a 1-meter-long germanium trunk fiber connected to a 1-cm-long silica fiber tip using PTFE, PET, or PTFE/FEP heat-shrink tubing. Maximum transmission of Er:YAG energy through fiber trunk/tip diameters of 250/365, 350/365, and 450/550 μm were recorded. The transmission rates through 450/550 μm fibers using Q-switched (500 ns) and free-running (300 μs) Er:YAG and Er:YSGG laser pulses were also measured. Maximum free-running Er:YAG pulse energies (fluences) measured up to 103 mJ (98 J/cm 2), 112 mJ (107 J/cm 2), and 233 mJ (98 J/cm 2), respectively, through 250/365, 350/365, and 450/550 hybrid fibers. Free-running Er:YAG and Er:YSGG transmission averaged 56% and 65%, with an attenuation of 1.1 ± 0.1 dB/m and 0.6 ± 0.1 dB/m, respectively, after correction for Fresnel losses (n = 7). Q-switched Er:YAG and Er:YSGG laser transmission averaged 55% and 62%, with an attenuation of 1.1 ± 0.2 dB/m and 0.9 ± 0.3 dB/m, respectively. Both Q-switched lasers transmitted a maximum pulse energy of 13 mJ (n = 7). The germanium/silica fiber is promising for use with the Erbium laser in applications requiring contact laser tissue ablation through a flexible endoscope.

Original languageEnglish (US)
Title of host publicationProgress in Biomedical Optics and Imaging - Proceedings of SPIE
EditorsI. Gannot
Number of pages5
StatePublished - 2005
EventOptical Fibers and Sensors for Medical Applications V - San Jose, CA, United States
Duration: Jan 22 2005Jan 25 2005


OtherOptical Fibers and Sensors for Medical Applications V
Country/TerritoryUnited States
CitySan Jose, CA


  • Erbium
  • Fiber
  • Germanium
  • Hybrid
  • Mid-IR
  • Oxide glass
  • Q-switched

ASJC Scopus subject areas

  • Engineering(all)


Dive into the research topics of 'Transmission of free-running and Q-switched Er: YAG and Er:YSGG laser energy through germanium oxide/silica fibers'. Together they form a unique fingerprint.

Cite this