ANALYSIS OF HIGHLY-BIREFRINGENT FIBERS WITH A HOLLOW LAYER OUTSIDE ANELLIPTIC-CORE

The improved point-matching method with Mathieu function expansion for the accurate analysis of the W-type elliptical fiber with layers of a ny ellipticity is proposed. Results of our method are reliable, becaus e we expand the electromagnetic fields by a sum of the complete set of wave functions in each layer of the fiber. Numerical results are pres ented for the highly-birefringent fibers with a hollow layer outside a n elliptical core. It is found that such fibers can realize the large value of the modal birefringence as well as they can be suitable for t he single-mode and single-polarization transmission. From the converge nce tests, it is confirmed that the relative error of the modal birefr ingence is less than 0.01%. The comparison of our results with those b y previously reported method is presented. The proposed method can be extended for analysis of the elliptical-core fibers with hollow pits a nd electromagnetic scattering by targets of the complex elliptical geo metry.