A square core optical fiber

Abstract

The invention relates to a square core optical fiber, which includes a core layer and a cladding layer. The aspect ratio a / b of the core layer is 1-12, and the relative refractive index difference Δ1 of the core layer is 0%-2.2%. The beneficial effect of the present invention is that: the rectangular fiber core can improve the mode field matching and coupling efficiency between the optical fiber and the rectangular waveguide on the chip, and improve the mode division multiplexing performance of few-mode and multi-mode optical fiber transmission systems; the present invention can be combined with semiconductor laser output The mode at the end is well matched, which can improve the coupling efficiency, and is widely used in semiconductor laser fiber combiner components, etc. The aspect ratio of the fiber core and the core-cladding ratio of the invention are easy to control, the optical fiber attenuation is low, and the invention has great advantages in meeting different application requirements.

Description

technical field [0001] The invention relates to a square-core optical fiber and belongs to the technical field of optical fibers. Background technique [0002] Optical fiber communication has the characteristics of large transmission capacity, long transmission distance, and fast transmission rate, and is widely used in optical communication networks such as long-distance trunk networks, metropolitan area networks, and access networks. Driven by the demand for high-speed broadband data transmission services, the number of optical communication network users and new network data services continue to increase. In order to meet the increasing demand for network capacity, optical communication systems use various multiplexing technologies of optical signals in optical fibers, including wavelength division multiplexing (WDM), polarization division multiplexing (PDM), frequency division multiplexing ( FDM) and time division multiplexing (TDM). However, the multiplexing technolog...

AI Technical Summary

Problems solved by technology

However, the optical fiber in the semiconductor laser fiber energy beam assembly is generally a traditional optical fiber, and its core structure is circular, which is not well matched with the mode of the output end of the semiconductor laser, and the coupling efficiency is difficult to improve, which limits the application range of the semiconductor laser.

[0006] Patent CN107132612A proposes a rectangular core fiber, including a rectangular core in cross section, a ravine layer with a rectangular cross section boundary, a refractive index buffer layer and an outer cladding with a rectangular cross section boundary, and the refraction between the outer cladding and the core The absolute value of the rate difference is less than 0.0005, the length of the long side of the fiber core is twice the length of the short side, the optical fiber has a large fundamental mode field area in the case of bending, and the refractive index of the gully layer is the refractive index of each medium The lowest rate makes the high-order mode in the fiber core have greater transmission loss, while the fundamental mode has better transmission performance. The fiber adopts MCVD to deposit a multi-layer structure and core layer with high and low refractive index alternately distributed on the inner wall of a rectangular quartz tube. , but the deposition process in the rectangular quartz tube is difficult to control and the feasibility is poor

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