Comparative analysis of propagation characteristics of two triangular lattice photonic crystal fibers in the middle infrared spectrum

In this paper, a numerical comparison of optical performances of chalcogenide based PCFs with hexagonal and octagonal symmetry has been performed in the mid-IR spectrum for the first time. A tapering factor has been introduced to investigate the effects of core size for both the cases. Qualitative analysis of group velocity dispersion has been presented for a bandwidth of 3500 nm. Later, air filling fraction has been considered to shift the dispersion profile to anomalous region for the two cases. Finally, effective area method has been applied to find the cut-off region in the phase diagram. It has been found that improvement of bandwidth in O-PCF over H-PCF is subject to air filling fraction and operating wavelength.