Design of broadband dispersion compensating photonic crystal fiber with circularly distributed holes for optical communication applications
摘要
This study presents the design and analysis of a circular photonic crystal fiber (C-PCF) for broadband dispersion compensation. In order to construct the design, the dispersion profile of a regular C-PCF is tailored to achieve the desired dispersion profile required for compensating the unwanted dispersion of standard telecommunication fibers. The dispersion tailoring is carried out by manipulating and modifying the geometrical structure of a regular C-PCF. A finite difference mode analysis algorithm has been employed to investigate the effects of structural perturbations on the dispersion profile. In this approach, the transverse cross-section of the C-PCF is discretized into a two-dimensional finite difference grid, and an initial field profile is defined over the domain, which evolves as a guided mode of the structure through repeated application of Helmholtz equation in recurrence form. An appropriate design of PCF (photonic crystal fiber) geometry successfully attains a high negative dispersion value up to − 1,030 ps/nm/km and relative dispersion slope equal to 0.0035 nm-1, which exactly matches with that of standard single-mode fiber at 1550 nm working wavelength. Additionally, it is demonstrated that by allowing only ± 0.6% deviation in compensation ratio around the full compensation, effective dispersion within ± 0.1 ps/nm/km across a large band of 170 nm (1450–1620 nm) wavelengths can be obtained by using the proposed design. It is also found that residual dispersion remains within ± 10 ps/nm after compensating the accumulated dispersion in 100 km of long transmission fiber by just 1.6 km of C-PCF, which ensures its application in high-speed wavelength division multiplexing (WDM) systems.