Study of the linearly polarized modes and power analysis of double-clad refractive index profile of a dispersion flattened step index fiber

Design of double-clad or W refractive index profile of a dispersion flattened step index fiber which enables the understanding of various LP modes and their 2D as well as radial, intensity and amplitude plots. This index profile results in achieving high power in core for different values of core radius and waist radius of incident Gaussian beam. A comparative study is presented in this paper at three operating wavelengths. Optimal power in core (99.4 %) is observed at 1550nm for dispersion flattened fibers considering Fresnel reflection at the input end of the fiber.

I. INTRODUCTION

The double-clad or W profile [1] as described in Figure 1 is a complex fiber design that helps in distributing the dispersion minimum over a wider spectral range and offers desirable characteristics over a wide span of wavelengths. These fibers are suitably known as dispersion flattened fibers [2]. Mode [3] is a mathematical and physical concept describing the propagation characteristics of electromagnetic waves through media. In case of a fiber, a mode is simply a path that a ray of light can follow in traveling down a fiber.