Mechanical stress sensors using micromachined grating fibers

Hironori Kumazaki, Munehiro Hiramatsu, Hisakazu Oguri, Seiki Inaba, Kazuhiro Hane

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


We discuss mechanical stress sensors based on fiber Bragg gratings (FBGs) micromachined by anisotropic reactive ion etching (RIE) using CF4 plasma. Locally thinned FBGs have the potential to be used as sensitive strain sensors whose sensitivities increase with decreasing measurement range. The center reflection wavelength shift rate of an etched and thinned grating (thinned grating length: 2.0 mm; thinned diameter: 15 μm; total grating length: 10.0 mm) was approximately 15 times greater than that of a conventional unprocessed FBG. The difference in the center reflection wavelengths of thinned and unetched grating regions could be used to counteract changes in the surrounding temperature. On the other hand, a single FBG with an asymmetrical cross section can detect the degree of curvature and the bending direction. The center reflection wavelength shifted by 0.4 nm at 1550 nm on bending that imparted a radius of curvature of ±127 mm.

Original languageEnglish
Title of host publication21st International Conference on Optical Fiber Sensors
Publication statusPublished - 2011 Jun 9
Event21st International Conference on Optical Fiber Sensors - Ottawa, ON, Canada
Duration: 2011 May 152011 May 19

Publication series

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


Other21st International Conference on Optical Fiber Sensors
CityOttawa, ON


  • Anisotropic etching
  • Curvature sensor
  • Micromachined FBG
  • Strain sensor

ASJC Scopus subject areas

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


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