Improved performance of optical fiber core: role of plasmonic metals activation

Abstract

Optical fiber core with customized characteristics became demanding for diverse high performance applications. Based on this idea, the optical fiber core was activated using various plasmonic metals (beryllium, chromium, and nickel) to improve its refractive index, sensitivity and bandwidth. The influence of various wavelengths and core radii on three modes (LP01, LP11 and LP21) propagation was determined using finite element analysis (FEM). The COMSOL MULTIPHYSICS software was used for the computation. The fiber core radii of the plasmonic metal activated and wavelengths were varied to control the forward and backward energy propagation as well as the modal dispersion relation. Quantities like effective refractive index, attenuation, propagation constant and diffusion coefficient for the three modes as a function of wavelengths and fiber core radii were calculated, which showed maximum values at shorter wavelengths. Irrespective of the type of metal activation in the fiber core, the refractive index of LP01 mode for the core of radius 200 nm was more significantly affected compared to others. Regardless of different metals inclusion, the dispersion relation (refractive index versus frequency) for all modes was strongly positive, showing increasing values for radius in the order of 200, 400, 600 nm. Plasmonic metals Cr and Ni displayed best effect, while Be required high values of V to get LP01 in a narrow range and other modes appeared in a larger range than V. Present results may be useful for the development of high performance optical fiber core.