volume | PIER Journals

2004-12-13

Elliptical and Circular Step-Index Fibers with Conducting Helical Windings on the Core-Cladding Boundaries for Different Winding Pitch Angles - a Comparative Modal Dispersion Analysis

Deepak Kumar,

Dr. Deepak Kumar

Multimedia University

Malaysia

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Onkar Singh II

Dr. Onkar Singh II

Department of Applied Physis

Banaras Hindu University

India

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Progress In Electromagnetics Research, Vol. 52, 1-21, 2005

doi:10.2528/PIER04052002 | Google Scholar

Abstract

The propagation characteristics of an elliptical step-index fiber with a conducting helical winding on the core-cladding boundary are investigated analytically and compared with those of a circular step index fiber with a conducting radial winding. Our optical waveguides are unconventional: in view of the existence of helical conducting windings on the core-cladding boundaries. Appropriate coordinate systems, circular cylindrical and elliptic cylindrical, are chosen for the circular and elliptical fibers. Applying the boundary conditions as modified by the presence of conducting helical windings, the characteristic equations are obtained for both the fibers. Dispersion curves are also obtained for two special values of the helical pitch angle ψ, namely, for ψ = 0º and ψ = π/2 for each fiber and the results have been compared. It is found that the introduction of the helical winding has two main effects on the characteristics of both types of fibers. These are: (1) The helix introduces band gaps and (2) has the effect of splitting a mode into a pair of adjacent modes In the case of the elliptical helically clad waveguide we find two band gaps for V < 30 whereas for circular guide we have only one band gap in the same range of V-values, V being the normalized frequency parameter.

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Deepak Kumar, and Onkar Singh II, "Elliptical and Circular Step-Index Fibers with Conducting Helical Windings on the Core-Cladding Boundaries for Different Winding Pitch Angles - a Comparative Modal Dispersion Analysis," Progress In Electromagnetics Research, Vol. 52, 1-21, 2005.
doi:10.2528/PIER04052002

References

1. Marcuse, D., Theory of Dielectric Waveguides, Academic Press, 1974.

2. Adams, M. J., An Introduction to Optical Waveguides, 250-257, 250-257, 1981.

3. Cherin, A. H., An Introduction to Optical Fibers, 85-98, 85-98, 1987.

4. Snyder, A. W. and J. D. Love, Optical Waveguide Theory, 248-255, 248-255 and 311-315, 1983.

5. Gloge, D., "Dispersion in weakly guiding fibers," Appl. Opt., Vol. 10, 2442-2445, 1971. Google Scholar

6. Gloge, D., "Propagation effects in optical fibers," IEEE Trans. Microwave Theory Tech., Vol. 23, 106-120, 1975.
doi:10.1109/TMTT.1975.1128511 Google Scholar

7. Gloge, D., "Weakly guiding fibers," Appl. Opt., Vol. 10, 2252-2258, 1971. Google Scholar

8. Chu, L. J., "Electromagnetic waves in elliptic hollow pipes of metal," J. Appl. Phy., Vol. 9, 583-591, 1938.
doi:10.1063/1.1710459 Google Scholar

9. Dyott, R. B. and J. R. Stern, "Group delay in glass fiber waveguides," Electronics Letters, Vol. 7, 82-84, 1971. Google Scholar

10. Singh, U. N., O. N. Singh II, P. Khastgir, and K. K. Dey, "Dispersion characteristics of a helically cIadded step-index optical filber analytical study," J. Opt. Soc. Am. B, 1273-1278, 1995. Google Scholar

11. Kumar, D. and O. N. Singh II, "Modal characteristics equation and dispersion curves for an elliptical step-index fiber with a conducting helical winding on the core-cladding boundary — An analytical study," IEEE Journal of Light Wave Technology, Vol. 20, No. 8, 1416-1424, 2002.
doi:10.1109/JLT.2002.800799 Google Scholar

12. Kumar, D. and O. N. Singh II, "Some special cases of propagation characteristics of an elliptical step-index fiber with a conducting helical winding on the core-cladding boundary — An analytical treatment," Optik, Vol. 112, No. 12, 561-566, 2001. Google Scholar

13. Kumar, D. and O. N. Singh II, "An analytical study of the modal characteristics of annular step-index waveguide of elliptical cross-section with two conducting helical windings on the two boundary surfaces between the guiding and the non-guiding regions," Optik, Vol. 113, No. 5, 193-196, 2002. Google Scholar

14. Watkins, D. A., Topics in Electromagnetic Theory, John Wiley and Sons Inc., 1958.

15. McLachlan, N. W., Theory and Application of Mathieu Functions, Oxford University Press, 1947.

16. Abramowitz, M. and I. A. Stegun, Handbook of Mathematical Functions, Dover Publications, 1965.

17. Tai, C.-T., Generalized Vector and Dyadic Analysis, IEEE Press, 1992.