Optical power confinement factor in a Bragg fiber: 2 Numerical results

Abstract

We present numerical results on the optical power confinement factor Γ for the TE, TM, and hybrid modes in a Bragg fiber. In particular, ΓQWS under the quarter-wave stack condition is useful for understanding various properties. We calculate Γ and ΓQWS as a function of the core radius, cladding index contrast, and so on. Numerical results reveal that the TE01 mode shows the highest value of ΓQWS among all the modes over most of the parameter ranges. This result corresponds well to that seen in the circular metallic waveguide. The ΓQWS of the TE01 mode is 99% for the cladding index contrast of na−nb=0.48, and the ratio of the core radius to wavelength rc/λ0=2.0. An optimum value for the cladding lower index is shown as a function of the cladding index contrast.