A single mode ultra flat high negative residual dispersion compensating photonic crystal fiber

•The designed fiber offers ultraflattened negative dispersion ranging from 980 to 1580 nm wavelength band.•Average dispersion of −138 ps/(nm km) with an dispersion variation of 12 ps/(nm km) is obtained.•The proposed fiber successfully operates as a single mode fiber in the entire band of interest.•Very large nonlinearity of 33.6 W−1 K m−1 is found at 1550 nm.

In this paper, a single mode photonic crystal fiber based on hexagonal architecture is numerically demonstrated for the purpose of residual dispersion compensation in the wavelength range of 980–1580 nm. The designed fiber offers ultraflattened negative dispersion in the near-infrared to most widely used S to L wavelength bands and average dispersion of about −138 ps/(nm km) with an absolute dispersion variation of 12 ps/(nm km). Besides, the proposed fiber successfully operates as a single mode in the entire band of interest. Moreover, to check the dispersion accuracy, sensitivity of the fiber dispersion properties to a ±1–5% variation in the optimum parameters is studied for practical conditions.