Single mode fiber

Abstract

The invention relates to a single mode fiber with the lower manufacturing cost. The single mode fiber comprises a core layer, wherein a first inner wrapping layer, a second inner wrapping layer and an outer wrapping layer wrap the core layer in sequence. The single mode fiber is characterized in that the outer wrapping layer is made of natural siliceous sand, the absolute refraction index of the outer wrapping layer ranges from 1.4572 to 1.4574, the diameter alpha of the core layer is 8-10 micrometers, the refraction index difference delta n1 of the core layer and the outer wrapping layer ranges from 4.1*10<-3> to 6.4*10<-3>, the ratio b / a of the diameter b of the first inner wrapping layer to the diameter a of the core layer is greater than or equal to 1.6, the refraction index difference delta n2 of the first inner wrapping layer and the outer wrapping layer ranges from -2.4*10<-3> to -0.7*10<-3>, and the ratio c / a of the diameter c of the second inner wrapping layer to the diameter a of the core layer is greater than or equal to 3.6. The outer wrapping layer of an optical fiber prefabricated bar is made of the natural siliceous sand with the lower cost, so that the manufacturing cost of the optical fiber is lowered greatly; the structure of the inner wrapping layers and the outer wrapping layer is adopted, the ratio of the inner wrapping layers to the core layer is selected reasonably, and the fluorine mixing amount and the chloride ion concentration in the second inner wrapping layer are controlled, so that influence on optical attenuation from the impurities of the outer wrapping layer made of the natural siliceous land is reduced, and the water peak performance and the attenuation coefficient of the single mode fiber are reduced effectively.

Description

technical field [0001] The invention relates to the technical field of optical communication, in particular to a single-mode optical fiber used in an optical communication transmission system with relatively low manufacturing cost. Background technique [0002] With the increasingly fierce competition in the optical fiber market, the market price of optical fiber has become a means of competition for more and more manufacturers. Improving the overall efficiency of the manufacturing process and reducing the manufacturing cost of optical fibers have attracted more and more attention. Increasing the size of the preform, prolonging the drawing time of a single preform, and improving the utilization of equipment are an effective means to improve the overall efficiency of production. At present, various optical fiber manufacturers are maximizing the drawing length of the optical fiber corresponding to a single optical fiber preform. Since the glass forming the cladding part of t...

AI Technical Summary

Problems solved by technology

However, in order to prepare large preforms with low water peaks, the technical route of out-of-tube + Soot direct outsourcing method also has shortcomings: a. The out-of-tube method has a separation process of Soot preparation and vitrification, and the process is relatively complicated; b. In the realization of complex refractive index Compared with the in-tube method, the cross-section and Ge / F co-doping process are obviously insufficient

The former can only rely on the purity of raw materials, which is difficult to control artificially

In addition, due to the limited purification methods of natural quartz materials, the content of metal impurities is relatively high, and it is difficult to control artificially.

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