Dispersion Tailoring in Circular Photonic Crystal Fibers for Ultraflattened Dispersion

In order to tailor the dispersion characteristics and to control the dispersion slope of index-guiding photonic crystal fibers (PCFs), a new controlling technique is reported. Moreover, this technique is applied to design PCF with both near zero and ultraflattened dispersion in a large wavelength range. The birefringence of the fiber is also addressed as the field profile becomes elliptical in the designed fiber. In addition, how the inevitable imprecision introduced during the fabrication process affects the final dispersion profile is investigated. A finite difference method is used to analyze the dispersion properties and the birefringence characteristics of the PCF. Simulation results reveal that ultraflattened dispersion of 0 ± 1.5 ps/(nm.km) can be achieved over a bandwidth of 890 nm in the wavelength region of 1110-2000 nm along with polarization maintaining property.