Loss and nonlinearity are the most critical factors affecting the performances of 100Gbit/s optical communication systems.This letter designs and develops a novel single-mode fiber for 400Gbit/s high-rate transmissions.With ultra-low-loss and super-large effective area characteristics

its attenuation coefficients are reduced to 0.165 dB/km at 1 550 nm and0.179dB/km at 1 625 nm respectively.The mode-field-diameter is 13.96μm at 1 550 nm

and the effective area is 153μm2.Moreover

this fiber has outstanding anti-bending performance and its key technological specifications are superior to the current international technological level and can provide the key fundamental material support to the next generation high-rate fiber-optic communications.