Sensor applications of photosensitive capillary waveguides

We describe a photosensitive capillary waveguide sensor, composed of a capillary structure with a photosensitive cladding ring surrounding the bore. The bore is filled with a fluid having an index of refraction that is sensitive to a measurand of interest, and a grating is inscribed in the cladding ring. We measure the optical interaction between light propagating in the filled capillary waveguide and the grating to determine the parameter of interest. Methods for forming connections between the capillary and single mode optical fiber are also described. We demonstrate the performance of the capillary waveguide as a temperature sensor in which the sensitivity of the Bragg wavelength to temperature is -150 pm/°C. We also describe how to use the capillary waveguide sensor to discriminate between different measurands.

[1]  Eric Udd,et al.  Fiber Optic Sensors , 1992 .

[2]  Min-Suk Kwon,et al.  In-line polarization controller that uses a hollow optical fiber filled with a liquid crystal. , 2004, Optics letters.

[3]  Kevin H. Smith,et al.  Bragg Grating Temperature Sensor in Photosensitive Capillary Waveguide , 2006 .

[4]  Kyriacos Kalli,et al.  Fiber Bragg Gratings: Fundamentals and Applications in Telecommunications and Sensing , 2000 .

[5]  G. Peng,et al.  Thermal tuning of polymer optical fiber Bragg gratings , 2001, IEEE Photonics Technology Letters.

[6]  P. Pérez-Millán,et al.  Temperature sensor based on the power reflected by a Bragg grating in a tapered fiber. , 2004, Applied optics.

[7]  J.W. Yu,et al.  Novel all-fiber bandpass filter based on hollow optical fiber , 2002, IEEE Photonics Technology Letters.

[8]  T. Erdogan.  Fiber grating spectra , 1997 .

[9]  V. Bhatia.  Applications of long-period gratings to single and multi-parameter sensing. , 1999, Optics express.

[10]  K. Hill,et al.  Photosensitivity in optical fiber waveguides: Application to reflection filter fabrication , 1978 .

[11]  I. Bennion,et al.  Spectral characteristics of tapered LPG device as a sensing element for refractive index and temperature , 2006, Journal of Lightwave Technology.

[12]  Byoungho Lee,et al.  Electrically controllable long-period liquid crystal fiber gratings , 2000 .

[13]  Ian Bennion,et al.  Sensitivity characteristics of long-period fiber gratings , 2002 .

[14]  M. Litorja,et al.  Low-loss liquid-core optical fiber for low-refractive-index liquids: fabrication, characterization, and application in Raman spectroscopy. , 1997, Applied optics.

[15]  Pieter L. Swart,et al.  Study of hydrogen diffusion in boron/germanium codoped optical fiber , 2002 .

[16]  Michael A. Davis,et al.  Fiber grating sensors , 1997 .