Ge-Doped Defect-Core Microstructured Fiber Design by Genetic Algorithm for Residual Dispersion Compensation

A special microstructured optical fiber, which may be used in a wavelength-division-multiplexing (WDM) optical fiber transmission system for residual chromatic dispersion compensation, is designed and analyzed. The proposed structure is obtained by introducing a small Ge-doped core at the center of a conventional photonic crystal fiber. The behavior of the resulting geometry has been optimized by a genetic algorithm in conjunction with an efficient vectorial finite element formulation. Numerical results show that the designed photonic crystal fiber exhibits flattened negative dispersion over
$E + S + C + L + U$
wavelength bands with an average dispersion of
$-$
212
$\hbox{ps} \cdot \hbox{km}^{-1} \cdot \hbox{nm}^{-1}$
.