A photonic crystal fiber (PCF) with low confinement loss and nearly zero ultraflattened chromatic dispersion over ultra-broad wavelength is proposed. Some important PCF design parameters, such as the influences of the diameter of air holes and hole pitch on the confinement loss, chromatic dispersion has been thoroughly investigated by employing the full vectorial finite element method with anisotropic perfectly matched layers. The simulation results show that the dispersion coefficient is <0.6 ps/(km⋅nm) and is larger than −0.5 ps/(km⋅nm) from 1.32 to 1.64 μm, and the confinement losses are <10 −7dB/m in the same wavelength range by introducing extra air holes in the same ring.
"Characteristics analysis of large solid-core square-lattice photonic crystal fibers with hybrid cladding," Optical Engineering 53(1), 016112 (21 January 2014). https://doi.org/10.1117/1.OE.53.1.016112