Design and Analysis of Dispersion Flattened Low Loss Photonic Crystal Fiber

Abstract

This paper demonstrates the study of triangular lattice hexagonal photonic crystal fiber with GeO₂ doped core. The photonic crystal fiber (PCF) studied in this research work has a core doped with 97% molar concentrated GeO₂ with seven layers of air-capillaries around the core. The design and analysis of optical characteristics, i.e., dispersion, confinement loss, and effective area have been studied extensively for optimizing the structure for a certain range of operating wavelengths. Modal analysis of the proposed geometry has been performed for a wide range of wavelengths (1200–1650 nm) targeting two particular wavelengths, i.e., 1310 and 1550 nm. Achieving nearly zero dispersion with flat dispersion curve, low confinement loss, and low effective area have been the main focus of our research. The simulations were conducted with COMSOL Multiphysics 5.0 software using finite element method. Investigated mode field in all cases shows stronger confinement of fundamental mode in the fiber core. Optimization of the global parameters led to obtain values of dispersion, confinement loss, and effective area, 8.769 ps/(nm-km), 2.731×10^–8 dB/km, 0.7409 µm² at the wavelength of 1310 nm and 5.322 ps/(nm-km), 3.126×10^–9 dB/km, 0.928 µm² at the wavelength of 1550 nm, respectively. The result suggests the proposed hexagonal photonic crystal fiber to be a good candidate for broadband super-continuum generation, optical coherence tomography, time resolved absorption, spectroscopy, fiber sensor, and wavelength conversion.

Keywords: Hexagonal photonic crystal fiber (H-PCF), finite element method (FEM), dispersion, confinement loss, effective area