Evanescent wave delivery into a precise tissue area using fiber-optic probes

I. K. Ilev, R. W. Waynant, M. A. Bonaguidi

Research output: Contribution to journalArticle


We demonstrate a novel all-optical-fiber system for infrared (IR) laser radiation delivery into a precise tissue area. The operating principal of the laser delivery system is based on the use of a direct laser-to-taper coupling and an IR delivery fiber with angle-shaped tip. In our experiment, instead of a conventional lens-based laser-to-fiber coupling we use an uncoated glass hollow taper for a laser-to-fiber coupling. It is a funnel-shaped grazing-incidence-based hollow taper. The laser emission is launched directly, without any focusing elements, into the taper and next into the delivery fiber by a direct taper-to-fiber coupling. The IR fiber delivers the forward emission from a Er:YAG laser (λ=2.94 μm) to the tissue to be treated. Moreover, in order to realize a regime of evanescent wave delivery, we use a specially shaped fiber tip with an angled (porro-prism) profile. When the fiber tip is out of the tissue area, the laser emission is backreflected at the angled tip due to total-internal-reflection. However, when the fiber tip is placed on absorbing tissue, it becomes "transparent" for laser emission because of the frustrated-total-internal-reflectance and the energy then is coupled into the absorber. When sufficient energy is transferred, dermatology or other precise surgical processes can be controlled or stopped.

Original languageEnglish (US)
Pages (from-to)161-167
Number of pages7
JournalProceedings of SPIE - The International Society for Optical Engineering
StatePublished - Jan 1 2001


  • Evanescent wave delivery
  • Grazing incidence
  • Hollow taper
  • Optical fiber

ASJC Scopus subject areas

  • Electronic, Optical and Magnetic Materials
  • Condensed Matter Physics
  • Computer Science Applications
  • Applied Mathematics
  • Electrical and Electronic Engineering

Fingerprint Dive into the research topics of 'Evanescent wave delivery into a precise tissue area using fiber-optic probes'. Together they form a unique fingerprint.

Cite this