Optical fiber large in effective area

Abstract

The invention relates to an optical fiber large in effective area. The optical fiber large in the effective area comprises a fiber core layer and a covering layer. The optical fiber large in the effective area is characterized in that the fiber core layer comprises an inner core layer and an outer core layer, the radius r1 of the inner core layer is 1 to 4 microns, a relative refractive index difference delta 12 of the inner core layer to the outer core layer meets the condition that -0.2% <= delta 12 < 0%, the relative refractive index difference of the inner core layer to the outer core layer is invariant or gradually increased along with increasing of the radius, the radius r2 of the outer layer is 4 to 7 microns, and the relative refractive index difference delta 2 of the outer core layer is -0.15 % to 0.05 %; the covering layer comprises an inner covering layer, a sunk concave covering layer and an outer covering layer, the inner covering layer covers the fiber core layer, the radius r3 of the inner covering layer is 7 to 20 microns, the relative refractive index difference delta 3 is within the range of -0.5 % to -0.1 %, the radius r4 of the sunk concave covering layer is 12 to 40 microns, the relative refractive index difference delta 4 is within the range of -1.0 % to -0.3 %, and the relative refractive index difference delta 5 is within the range of -0.2% to -0.4%. The optical fiber large in the effective area has a large effective area, quite low transmission loss and good curve characteristics, and is particularly suitable for application of a long-distance high-speed large-volume communication system.

Description

technical field [0001] The invention relates to an optical fiber, in particular to a single-mode optical fiber with low attenuation and large effective area. Background technique [0002] With the development of international communication services, especially the rapid development of Internet technology and 3G and passive optical network technologies, the demand for optical fiber bandwidth in communication systems shows a rapid growth trend. In communication systems with long-distance, large-capacity, and high-speed transmission, fiber amplifier technology and wavelength division multiplexing technology are usually required, especially in backbone networks and submarine communications. have higher requirements. However, the growth of transmission capacity and distance requires higher fiber input power and lower fiber loss to meet the requirement of resolvable signal-to-noise ratio. With the increase of the fiber input power, nonlinear effects such as sub-phase modulation,...

AI Technical Summary

Problems solved by technology

The second is to reduce the relative refractive index of the core layer, so that the light field distribution is flatter, thereby increasing the effective area, and at the same time reducing the cut-off wavelength, but it has a negative impact on the fiber attenuation

[0008] Although the change of the core layer structure and the increase of the core layer size bring about an increase in the effective area, it will also deteriorate the bending performance of the optical fiber and the attenuation performance of the optical fiber. In order to take into account the bending performance of the optical fiber, the effective area of ​​the optical fiber in the above patents The added value is limited

In the patents seen, no effective area larger than 135μm has been seen 2 - , and maintain good bending performance of the fiber

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