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IEEE Journal of Lightwave Technology
Volume 18 Number 9, September 2000

Table of Contents for this issue

Complete paper in PDF format

Analysis of Core-Mode to Radiation-Mode Coupling in Fiber Bragg Gratings with Finite Cladding Radius

Yahei Koyamada Member, IEEE

Page 1220.

Abstract:

Fiber Bragg gratings (FBGs) are often surrounded with dielectric material whose refractive index is higher than that of cladding. The purpose is to prevent cladding modes because coupling to cladding modes may cause undesirable dips on the short wavelength side of the main Bragg band in the core-mode transmission spectrum. In such FBGs, core-mode to radiation-mode coupling can cause a loss band continuum. Until now, however, reported analyses of this core-mode to radiation-mode coupling have been limited to hypothetical FBGs with an infinite cladding radius. This paper presents, to the best of our knowledge, the first analysis of core-mode to radiation-mode coupling in real FBGs with a finite cladding radius. We derive a formula to calculate the core-mode transmission loss caused by the radiation-mode coupling. We show calculated core-mode transmission spectra that exhibit such fringes as have already been observed experimentally but not yet theoretically estimated.

References

  1. "Special issue on fiber gratings, photosensitivity and poling", J. Lightwave Technol., vol. 15, pp.  1263-1512, Aug.  1997 .
  2. T. Erdogan, "Fiber grating spectra", J. Lightwave Technol. , vol. 15, pp.  1277-1294, Aug.  1997.
  3. T. Erdogan, "Cladding-mode resonances in short and long period fiber grating filters", J. Opt. Soc. Amer. A, vol. 14, pp.  1760-1773, Aug.  1997.
  4. V. Mizrahi and J. E. Sipe, "Optical properties of photosensitive fiber phase grating", J. Lightwave Technol., vol. 11, pp.  1513-1517, Oct.  1993.
  5. T. Erdogan and J. E. Sipe, "Tilted fiber phase gratings", J. Opt. Soc. Amer. A, vol. 13, pp.  296-313, 1996.
  6. D. Marcuse, Theory of Dielectric Optical Waveguides, 2nd ed.   New York, NY: Academic, 1991.