A design of novel photonic crystal fiber with low and flattened dispersion for supporting 84 orbital angular momentum modes

A dual-guided photonic crystal fiber(PCF) with low and flattened dispersion is designed, which can support a large number of orbital angular momentum(OAM) modes. The properties of the proposed PCF are systematically analyzed through the finite element method. The results show that the proposed PCF can support up to 84 OAM modes with 600 nm bandwidth ranging from 1000 to1600 nm. All values of mode purity are above 91.7%, the isolation parameters are larger than 67 dB and the maximum value up to 145 dB, the lowest confinement loss is only 5×10dB·m.More importantly, the values of dispersion for all modes are less than 40 ps·km·nm, and the lowest dispersion variation is only 0.7 ps·km·nm. These superior optical properties make the proposed PCF have great advantage in stable transmissions of data and long-distance optical fiber communication system with large capacity.