Ultra-low attenuation single-mode optical fiber

The invention relates to an ultra-low attenuation single-mode optical fiber. The ultra-low attenuation single-mode optical fiber comprises a core layer and a wrapping layer. The ultra-low attenuation single-mode optical fiber is characterized in that the radius R1 of the core layer is 3.8-4.5[mu]m, and [delta]1 is -0.05%-0.12%; the core layer is externally covered by an inner wrapping layer, a first sunken inner wrapping layer, an intermediate inner wrapping layer, a second sunken inner wrapping layer, an auxiliary outer wrapping layer and an outer wrapping layer from inside to outside in sequence; the radius R2 of the inner wrapping layer is 8-15[mu]m, and [delta]2 is -0.35%- -0.15%; the radius R3 of the first sunken inner wrapping layer is 13-20[mu]m, and [delta]3 is -0.8%- -0.35%; the radius R4 of the intermediate inner wrapping layer is 16-23[mu]m, and [delta]4 is -0.45%- -0.15%; the radius R5 of the second sunken inner wrapping layer is 20-30[mu]m, and [delta]5 is -0.6%- -0.2%; the radius R6 of the auxiliary outer wrapping layer is 35-50[mu]m, and [delta]6 is -0.45%- -0.15%; and the outer wrapping layer is a pure silica glass layer. According to the invention, a relatively low attenuation coefficient is obtained, all optical parameters meet G.652.B standard requirements simultaneously, and relatively good bending loss and dispersion performance is realized.