Nearly Zero Ultra-Flattened Dispersion in Octagonal Photonic Crystal Fiber

The low confinement losses, relatively high nonlinearity, and wideband ultra-flattened chromatic dispersion are the crucial properties of the PCFs. Thus, in this research, a comprehensive study has been conducted to design a novel Octagonal PCF (Photonic Crystal Fiber) microstructure with an ultra-flattened dispersion profile through a vast range of optical communication band wavelengths with a large negative dispersion of nearly 0.6635 ps/nm/km at 1550 nm. This PCF design and simulative study have been made by using COMSOL multi-physics. The guiding features of the fiber have been analyzed numerically to solve the Maxwell equation of electromagnetic field by using the full vector finite element method with cylindrically perfect to match layer for strongly absorb the outgoing waves from the computational region. Moreover, Octagonal rings in the cladding region provide better confinement and flattened dispersion in O-band (1260 nm-1360 nm) and C-band (1530 nm-1565 nm) in comparison to honeycomb or hexagonal lattice structures. Our proposed model has a nearly zero ultra-flattened dispersion of ± 0.3028 ps/nm/km in a 1290 nm to 1620 nm with wavelength range (320 nm flat band) and low confinement loss is less than 10-7 dB/km in the entire band of interest. Furthermore, this research has been presented a 7.2 μm2 effective area which is smaller than other reported fibers at 1550 nm wavelength.