, Volume 6, Issue 4, pp 287–296 | Cite as

Leaky mode analysis of circular optical waveguides

  • Allan W. Snyder
  • D. J. Mitchell


A leaky mode is a bound mode below its cut-off frequency. It attenuates in the direction of propagation and approximates the portion of the radiation field within the optical waveguide that is significant far from the source. The characteristics, including attenuation coefficients, of leaky modes on the circular fibre are compared with those of the more familiar slab waveguide. Except for the HE1m leaky modes, leaky modes attenuate much faster on the slab than on the circular fibre. The greater the /(azimuthal field variation) the smaller the attenuatioN. Thus, theI≫1 leaky modes are important even at great distances from the source. An effective cut-off frequency is proposed. Above this frequency the mode is either weakly leaky or trapped. An expression for the number of weakly leaky and trapped modes is given. The power of leaky modes due to illuminating one end of the fibre is determined. The effect of material absorption is considered.


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Copyright information

© Chapman and Hall Ltd. 1974

Authors and Affiliations

  • Allan W. Snyder
    • 1
  • D. J. Mitchell
    • 1
  1. 1.Institute of Advanced Studies, Department of Applied MathematicsAustralian National UniversityCanberraAustralia

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