The paper deals with the propagation of electromagnetic waves through twisted clad dielectric optical fibers. The structure of these fibers is analogous to travelling wave tubes used in microwave devices, and the usefulness would be in the areas of optical sensing. This is because the twists in fiber would be affected due to the imposed stress and/or strain, leaving thereby the possibility to alter the propagation characteristics. A rigorous analytical investigation has been carried out with the emphasis on the energy flux density patterns due to the different propagating modes in the fiber. The dispersion relations of the system are deduced and the energy flux densities are evaluated under different pitch angles of twist. The effect due to conducting helix pitch on the electromagnetic wave propagation is emphasized.
2. Choudhury, P. K. and T. Yoshino, "Characterization of optical power confinement in a simple chirofiber," Optik, Vol. 13, 89-95, 2002.
3. Choudhury, P. K. and T. Yoshino, "A rigorous analysis of the power distribution in plastic clad annular core optical fibers," Optik, Vol. 113, 481-488, 2002.
4. Cheng, S. F. and L. K. Chau, "Colloidal gold-modified optical fiber for chemical and biochemical sensing," Anal. Chem., Vol. 75, 16-21, 2003.
5. Nair, A. and P. K. Choudhury, "On the analysis of field patterns in chirofibers," Journal of Electromagnetic Waves and Applications, Vol. 21, No. 15, 2277-2286, 2007.
6. Choudhury, P. K. and D. Kumar, "Towards dispersion relations for tapered core dielectric elliptical fibers," Optik, Vol. 118, 340-344, 2007.
7. Yeh, C. and I. F. Shimabukuro, The Essence of Dielectric Waveguides, Springer, New York, 2008.
8. Choudhury, P. K. and W. K. Soon, "TE mode propagation through tapered core liquid crystal optical fibers," Progress In Electromagnetics Research, Vol. 104, 449-463, 2010.
9. Amin, A. S. N., M. Mirhosseini, and M. Shahabadi, "Modal anal-ysis of multilayer conical dielectric waveguides for azimuthal invariant modes," Progress In Electromagnetics Research, Vol. 105, 213-229, 2010.
10. Duan, Z., Y. Wang, X. Mao, W.-X. Wang, and M. Chen, "Experimental demonstration of double-negative metamaterials partially filled in a circular waveguide ," Progress In Electromagnetics Research, Vol. 121, 215-224, 2011.
11. Kesari, V. and J. P. Keshari, "Analysis of a circular waveguide loaded with dielectric and metal discs," Progress In Electromagnetics Research, Vol. 111, 253-269, 2011.
12. Choudhury, P. K., "Dispersion behavior of gold-nanocoated dielectric optical fibers," Adv. in Mat. Sci. Eng., Vol. 2012, Article ID 214614, 1-7, 2012.
13. Baqir, M. A. and P. K. Choudhury, "On the energy flux through a uniaxial chiral metamaterial made circular waveguide under PMC boundary," Journal of Electromagnetic Waves and Applications, Vol. 26, No. 16, 2165-2175, 2012.
14. Zarifi, D., A. Abdolali, M. Soleimani, and V. Nayyeri, "Inhomogeneous planar layered chiral media: Analysis of wave propagation and scattering using Taylor's series expansion," Progress In Electromagnetics Research, Vol. 125, 119-135, 2012.
15. Choudhury, P. K., "Evanescent field enhancement in liquid crystal optical fibers - A field characteristics based analysis," Adv. in Condensed Mat. Phys., Vol. 2013, Article ID 504868, 1-9, 2013.
16. Dong, J. and J. Li, "Characteristics of guided modes in uniaxial chiral circular waveguides," Progress In Electromagnetics Research, Vol. 124, 331-345, 2012.
17. Baqir, M. A. and P. K. Choudhury, "Propagation through uniaxial anisotropic chiral waveguide under DB-boundary conditions," Journal of Electromagnetic Waves and Applications, Vol. 27, No. 6, 783-793, 2013.
18. Singh, U. N., O. N. Singh II, P. Khastgir, and K. K. Dey, "Dispersion characteristics of a helically cladded step-index optical fiber: An analytical study," J. Opt. Soc. Am. B, Vol. 12, 1273-1278, 1995.
19. Kumar, D., O. N. Singh, and II, "Modal characteristic equation and dispersion curves for an elliptical step-index fiber with a conducting helical winding on the core cladding boundary: An analytical study," J. Light. Tech., Vol. 20, 1416-1424, 2002.
20. Kumar, D., P. K. Choudhury, and F. A. Rahman, "Low eccentricity elliptical fibers with helical windings under slow-wave consideration - Some special cases," Optik, Vol. 121, 926-933, 2010.
21. Pierce, J. R., Travelling Wave Tubes, D. Van Nostrand, NJ, 1950.
22. Lim, K. Y., P. K. Choudhury, and Z. Yusoff, "Chirofibers with helical windings - An analytical investigation," Optik, Vol. 121, 980-987, 2010.
23. Choudhury, P. K., "Transmission through twisted clad liquid crystal optical fibers," Progress In Electromagnetics Research, Vol. 131, 169-184, 2012.
24. Kumar, D., P. K. Choudhury, and O. N. Singh, II, "Towards the dispersion relations for dielectric optical fibers with helical windings under slow- and fast-wave considerations - A comparative analysis," Progress In Electromagnetics Research, Vol. 80, 409-420, 2008.
25. Abramowitz, A. and I. A. Stegun, Handbook of Mathematical Functions, Dover, New York, 1970.
26. Adams, M. J., An Introduction to Optical Waveguides, 250-257, Wiley, UK, 1981.
27. Cherin, A. H., An Introduction to Optical Fibers, Chapt. 2, McGraw-Hill, New York, 1987.