Bend-insensitive single mode fiber and preparation method thereof

Abstract

Provided is a bend-insensitive single mode fiber and a preparation method thereof. An optical fiber wave guiding structure comprises a core layer and wrapping layers, wherein the wrapping layers comprise three sub wrapping layers, namely a first wrapping layer, a second wrapping layer and a third wrapping layer, the first wrapping layer and the third wrapping layer are both pure silica glass layers, the second wrapping layer is a mixed wrapping layer, the relative refractivity of the core layer and the relative refractivity of the three sub wrapping layers are all relative to the third wrapping layer. The wave guiding structure parameter is that the core layer relative refractivity delta 1 is not smaller than 0.30% and not larger than 0.85%, the core layer radius r is not smaller than 3.5 micrometers and not larger than 5.0 micrometers, the relative refractivity delta 2 of the second wrapping layer is not smaller than -55.00% and not larger than -45.00%, the radius r 2 of the second wrapping layer is not smaller than 8.0 micrometers and not larger than 15.0 micrometers, the refractive index of the first wrapping layer and the third wrapping layer is the refractive index nc of pure silica glass, the radius r 1 of the first wrapping layer is not smaller than 6.0 micrometers and not larger than 12.5 micrometers, and the radius r 3 of the third wrapping layer is not smaller than 62.0 micrometers and not larger than 63.0 micrometers. According to the preparation method of the bend-insensitive single mode fiber, a vapor-phase axial deposition method is used for manufacturing the core layer and the first wrapping layer, and then a casing pipe method is used for manufacturing the second wrapping layer and the third wrapping layer outside the core layer and the first wrapping layer. The bend-insensitive single mode fiber has the advantages of being small in additional loss, good in bending performance, high in mechanical strength and the like in a small bending radius, and the optical parameter and the geometric dimensioning are compatible with a G.652 optical fiber. The preparation method is simple in technology and convenient to operate.

Description

technical field [0001] The invention relates to an optical fiber and a preparation method thereof, in particular to a bend-insensitive single-mode optical fiber with excellent bending performance and a preparation method thereof. Background technique [0002] With the gradual development of fiber-to-the-home (FTTH) work, the amount of optical fiber access network construction has increased significantly, which requires single-mode optical fibers suitable for access networks to have the characteristics of small additional loss and high mechanical strength under small bending radii. Cabling construction and crimping while controlling splice loss to already laid fiber. [0003] At present, the bending radius of the G.652 standard optical fiber widely used in China is 25mm. Due to the limitation of the bending radius, the optical fiber cannot be bent and installed at a small angle at will. [0004] US Pat. No. 4,838,643 describes an optical fiber with a W-shaped waveguide struc...

AI Technical Summary

Problems solved by technology

However, it is difficult for the PCVD process to achieve ideal results in the moisture control and profile design of the optical rod at the same time.

The optical rod deposition speed and deposition efficiency are not high, which increases the production cost of the optical fiber preform

Moreover, the more complex the refractive index profile, the more stringent the requirements for the process, which is not suitable for mass production

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