Refractive index and geometrical structure measurement of a core-doped photonic crystal fiber

Y. Youk, S. Kim, K. Oh, J. Kobelke, K. Schuster, J. Kirchhof, D. Y. Kim

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

2 Citations (Scopus)


Using confocal scanning optical microscopy, we carried out a direct refractive index profiling technique of complex and non-symmetric structured optical fibers. Several improvements on the earlier design are proposed; a light emitting diode (LED) at 658 nm wavelength instead of a laser diode (LD) or He-Ne laser is used as a light source for better index precision, and a simple longitudinal linear scanning and a curve fitting techniques are adapted instead of a servo control for maintaining an optical confocal arrangement. Also, we have developed a novel technique to remove measurement noise generated by pinhole diffraction. This improved, straightforward, and robust method can be used to determine the refractive index profile of optical fibers by determining the reflectivity of a sample's surface. This technique is easy and repeatable, and we demonstrated the refractive index measurement of a core-doped photonic crystal fiber for the first time.

Original languageEnglish
Title of host publicationPhotonic Crystal Materials and Devices IV
Publication statusPublished - 2006
EventPhotonic Crystal Materials and Devices IV - San Jose, CA, United States
Duration: 2006 Jan 232006 Jan 26

Publication series

NameProceedings of SPIE - The International Society for Optical Engineering
ISSN (Print)0277-786X


OtherPhotonic Crystal Materials and Devices IV
Country/TerritoryUnited States
CitySan Jose, CA

All Science Journal Classification (ASJC) codes

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


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