An Optimal Design for Decreasing Dispersion in Photonic Crystal Fiber

Fiber optic transmission systems are friendly data transmission systems environmentally due to their low losses, high bandwidth and acceptable reliability. Therefore, they are often used for communication infrastructures. However, the effects of optical loss and dispersion can cause problems in fiber optic communications. In this paper, we mitigate these effects by using photonic crystals. The goal is to minimise the dispersion of the fibers by changing the photonic crystal fiber parameters. Specifically, we change the number, radius, and shape of the holes to minimise dispersion. A new photonic crystal fiber (PCF) is proposed with hexagonal grids of air holes and 11 layers in this structure. An optimal holes number, radius and distance between holes are used to obtain the least dispersion. Next, we use several elliptical and stellar holes to reduce dispersion. The germanium impurity is exploited in the PCF core as a defect. The addition of germanium impurity to the core causes the doping atoms reflect a stronger optical signal with the same attenuated input signal properties. The simulation results show that dispersion value is zero in three points at wavelengths between 1.48 and 1.55 mu m. In this wavelength range, the dispersion value was obtained between - 0.3 and 0.6 ps/(nm km).