Correspondence Between Effective Mode Area and Dispersion Variations in Defected Core Photonic Crystal Fibers

In the present paper, the impact of defect insertion in the core area of a large core HF7 fiber on the effective mode area and chromatic dispersion characteristics is investigated to enhance the performance parameters of photonic crystal fibers (PCF). The obtained results meet the requirements of the wideband high-speed optical transmission systems. A novel method for increasing the effective mode area of PCFs without increasing the hole pitch is presented that is based on the mode field distribution modification by defect insertion. Furthermore, it is shown that the dispersion curve is predictable from the effective mode area variations in response to changing the defect parameters. Based on the aforementioned characteristics, the first fully systematic procedure to design a large mode area, dispersion flattened, low-loss and single-mode PCF is presented and employed to design a defected core fiber with chromatic dispersion of 2.9 ± 0.5 ps/(km·nm) in the S + C + L communication band with effective mode area larger than 80 μm² in the same wavelength range with excellent loss and single-modeness properties.