SMALL CORE-DIAMETER GRADED-INDEX OPTICAL FIBER

摘要

Related to is a small core-diameter graded-index optical fiber, including a core layer and a cladding which includes an inner cladding layer, a depressed cladding layer, and an outer cladding layer from inside to outside thereof. The core layer has a parabolic refractive index profile with a distribution index α in a range from 1.9 to 2.1, a radius R1 in a range from 10 to 21 µm, and a maximum relative refractive index difference Δ1max in a range from 0.7% to 1.7% at a core layer center, and is a silica glass layer co-doped with germanium Ge, phosphorus P, and fluorine F. The inner cladding layer is a pure silica layer or an F-doped silica glass layer, and has a unilateral width in a range from 0.5 to 5 µm and a Δ2 in a range from -0.4% to 0%. The depressed cladding layer has a unilateral width in a range from 2 to 10 µm and a Δ3 in a range from -0.8% to -0.2%. The outer cladding layer is a pure silica glass layer. The optical fiber not only is compatible with existing OM3/OM4 multimode optical fibers, but also can support the wavelength-division multiplexing technology in a wavelength range from 850 nm to 950 nm. The optical fiber is also compatible with a single-mode optical fiber, and can support 1310 nm or 1550 nm single-mode transmission. The optical fiber has excellent bending resistance and is suitable for use in an access network or a miniaturized optical device.