Modal Propagation Properties of Elliptical Core Optical Fibers Considering Stress-Optic Effects

The effect of thermally induced stress on the modal properties of highly elliptical core optical fibers is studied in this work using a finite element method. The stress analysis is carried out and anisotropic refractive index change is calculated using both the conventional plane strain approximation and the generalized plane strain approach. After considering the stress optical effect, the modal analysis of the fiber is performed to obtain the solutions of fundamental and higher order modes. The modal effective index, modal birefringence, group effective index, group birefringence, and dispersion of different modes of the fiber are presented. For propagation properties, it can be seen that the results depend much on the approach of stress analysis.

Authors:

• M. Shah Alam
• Sarkar Rahat M. Anwar

Keywords:

• Birefringence
• dispersion
• elliptical core fiber
• optical mode analysis
• stress-optic effect
• stress analysis.

References:

[1] W. Urbanczyk, T. Martynkien, and W. J. Bock, "Dispersion effects in
elliptical-core highly birefringent fibers," Appl. Optics., vol. 40, no. 12,
pp. 1911-1920, April 2001.
[2] I. -K. Hwang, Y. -H. Lee, K. Oh, and D. N. Payne, "High birefringence
in elliptical hollow optical fiber," Optics Express, vol. 12, no. 9, pp.
1916-1923, May 2004.
[3] J. Noda, K. Okamoto, and Y. Sasaki, "Polarization-Maintaining Fibers
and Their Applications," IEEE J. Lightwave Technol., vol. LT-4. no. 8,
pp. 1071-1089, Aug. 1986.
[4] Y. Liu, B.M.A. Rahman, and K.T.V. Grattan, "Analysis of the
Birefringence Properties of Optical Fibers Made by a Preform
Deformation Technique," IEEE J. Lightwave Technol., vol. 13, no. 2,
pp. 142-147, Feb. 1995.
[5] Y. Liu, B. M. A Rahman, and K.T.V. Grattan, "Thermal-stress-induced
birefringence in bow-tie optical fibers," Appl. Optics, vol. 33, no. 24, pp.
5611-5616, Aug. 1994.
[6] K. Okamoto, Fundamentals of Optical Waveguides, Academic Press,
2000.
[7] K. Okamoto, T. Hosaka, and T. Edahiro, "Stress analysis of optical
fibers by a finite element method," IEEE J. Quantum Electron., vol. QE-
17, pp. 2123-2129, Oct. 1981.
[8] M. Fontaine, "Computations of optical birefringence characteristics of
highly eccentric elliptical core fibers under various thermal stress
conditions," J. Appl. Phys., vol. 75, no. 1, pp. 68-73, Jan. 1994.
[9] M. Fontaine, B. Wu, V. P. Tzolov, W. J. Bock, and W. Urbanczyk,
"Theoretical and Experimental Analysis of Thermal Stress Effects on
Modal Polarization Properties of Highly Birefringent Optical Fibers,"
IEEE J. Lightwave Technol., vol. 14, no. 4, pp. 585-591, Apr. 1996.
[10] M. Eguchi and M. Koshiba, "Accurate Finite-Element Analysis of Dual-
Mode Highly Elliptical-Core Fibers," IEEE J. Lightwave Technol., vol.
12. no. 4, pp. 607-613, Apr. 1994.
[11] M. Eguchi and M. Koshiba, "Behavior of the First Higher-Order Modes
of a Circular Core Optical Fiber Whose Core Cross-Section Changes
into an Ellipse," IEEE J. Lightwave Technol., vol. 13. no. 2, pp. 127-
136, Feb. 1995.
[12] T. Schreiber, H. Schultz, O. Schmidt, F. Roser, J. Limpert, and A.
Tunnermann, "Stress-induced birefringence in large-mode-area microstructured
optical fibers," Optics Express, vol. 13, no. 10, pp. 3637-
3645, May 2005.
[13] M. S. Alam, N. Somasiri, B. M. A. Rahman, and K. T. V. Grattan,
"Effects of High External Pressure on Photonic Crystal Fiber,"
Proceedings of the Third International Conference on Electrical and
Computer Engineering, ICECE 2004, Dhaka, Bangladesh, pp. 245-248,
Dec. 2004.
[14] Y. Jung, S. R. Han, S. Kim, U. C. Paek, and K. Oh, "Versatile control of
geometric birefringence in elliptical hollow optical fiber," Optics Lett.,
vol. 31, no. 18, pp. 2681-2683, Sept. 2006.
[15] H. Shu and M. Bass, "Calculating the Guided Modes in Optical Fibers
and Waveguides," IEEE J. Lightwave Technol., vol. 25, no. 9, pp. 2693-
2699, Sept. 2007.
[16] Y. Zhu, X. Chen, Y. Xu, and Y. Xia, "Propagation Properties of Single-
Mode Liquid-Core Optical Fibers With Subwavelength Diameter," IEEE
J. Lightwave Technol., vol. 25, no. 10, pp. 3051-3056, Oct. 2007.
[17] COMSOL Multiphysics, version 3.2, Sept. 2005.
[18] R. M. Anwar and M. S. Alam, "Thermal Stress Effects on Higher Order
Modes in Highly Elliptical Core Optical Fibers," Proceedings of the
Fifth International Conference on Electrical and Computer Engineering,
ICECE 2008, pp. 561-565 , Dhaka, Bangladesh, Dec. 2008.
[19] D. A. Nolan, G. E. Berkey, M. -J. Li, X. Chen, W. A. Wood, and L. A.
Zenteno, "Single-polarization fiber with a high extinction ratio," Optics
Lett., vol. 29, no. 16, pp. 1855-1857, Aug. 2004.
[20] E. M. Dianov and V. M. Mashinsky, "Germania-Based Core Fibers,"
IEEE J. Lightwave Technol., vol. 23, no. 11, pp. 3500-3508, Nov. 2005.