Comparison of chromatic dispersion of circular and hexagonal photonic crystal fibers with chloroform-core

In this paper, we compare dispersion characteristics of chloroform-core photonic crystal fibers (PCFs) with circular lattice and hexagonal lattice in the case of different air hole diameters. By varying lattice constant Ʌ and filling factor in the first ring d1/Ʌ, we can easily control chromatic dispersion and achieve three optimal structures for the circular lattice of fibers #CF1 (Ʌ = 1.0 µm, d1/Ʌ = 0.65), #CF2 (Ʌ = 1.0 µm, d1/Ʌ = 0.7), and #CF3 (Ʌ = 2.0 µm, d1/Ʌ = 0.3) and two optimal structures for the hexagonal lattice of fibers #HF1 (Ʌ = 1.0 µm, d1/Ʌ = 0.5), #HF2 (Ʌ = 2.0 µm, d1/Ʌ = 0.3). At the same structural parameter (Ʌ = 2.0 µm, d1/Ʌ = 0.3) and the corresponding pumping wavelength, the circular structure has a dispersion smaller by 5.598 ps/mn/km than the hexagonal lattice. #CF1 has all-normal dispersion with the peak of the dispersion curve asymptote to the zero-dispersion curve which is very suitable for coherent supercontinuum generation (SCG). The #HF1 structure has a near-zero flat anomalous dispersion in the wide wavelength range from 1.1 µm to 1.4 µm. Our results will be an important premise in choosing a PCF structure to study SCG.