The application provides an
optical fiber and a preparation method thereof, and relates to the field of optical fibers.The
optical fiber provided by the application comprises a
fiber core, a cladding, a stress layer and a
coating layer, the cladding is coated outside the
fiber core, the stress layer is embedded in the cladding, the stress layer has two, the two stress
layers are uniformly arranged around the periphery of the
fiber core, and the
coating layer is coated outside the cladding;the
radius a of the fiber core is 2.75-3.25 mu m, the
relative refractive index difference
Delta n1 of the fiber core is 0.5-1%;the
radius b of the cladding is 39-41 mu m, the cladding comprises a plurality of annular doped regions in a concentric circle structure in the radial direction of the cladding, the annular doped regions comprise a first annular region, the first annular region surrounds the fiber core outside, the
relative refractive index difference
Delta n2 of the first annular region is-0.1-0.3%, and the outer
radius r2 of the first annular region and the outer
diameter r1 of the inner circle of the first annular region satisfy the following relationship: (r2-r1) <= 3 mu m.The application provides an
optical fiber and a preparation method thereof, and the
coating layer of the optical fiber is not easy to fall off.