BEND-PROOF MULTIMODE OPTICAL FIBER

摘要

A bend-proof multimode optical fiber comprises a core layer and cladding layers. The cladding layers, from inner to outer, comprise an inner cladding layer, a sunken ring, a rising ring, and a sunken outer cladding layer. The core layer has the radius R1 being 23-27 microns, and the refractive index section of the core layer is a parabola. The unilateral thickness W2 of the inner cladding layer is 0-2.5 microns, and the relative refractive index difference 2 of the inner cladding layer is -0.1% to 0.1%. The unilateral thickness W3 of the sunken ring is 0.5-6 microns, and the minimum relative refractive index difference 3min of the sunken ring is -0.1% to -0.3%. The unilateral thickness W4 of the rising ring is 0.5-10 microns, and the rising ring is a pure silica layer. The unilateral thickness W5 of the sunken outer cladding layer is 17-39 microns, and the minimum relative refractive index difference 5min of the sunken outer cladding layer is -0.15% to -0.6%, and 3min > 5min. The multimode optical fiber has extremely low macro-bending attached attenuation, and has the same macro-bending flat feature at dual communication windows (850nm and 1300nm). In the optical fiber cladding layer the refractive index of the sunken ring is higher than that of the sunken outer cladding layer, and therefore the bandwidth of the bending-insensitive multimode optical fiber can be effectively improved.