Method utilizing medium with low melting point to realize fusion coupling of side face of optical fiber

Abstract

The invention provides a method utilizing a medium with low melting point to realize fusion coupling of the side face of an optical fiber. In the method, small-angle end face grinding and polishing are carried out on a pumping optical fiber; the medium with low melting point is uniformly adhered on the ground and polished inclined plane, and is then adhered to the side plane of an inner cladding of the dual-cladding optical fiber; and then two optical fibers are fused together by the medium with low melting point in heating fusion zones such as oxyhydrogen flames, a CO2 laser device, propane gas, a fine-particle blow lamp and the like. The medium with low melting point is a fusion medium, the melting point of the fusion medium is lower than that of the optical fiber, and the fusion medium comprises glass with low melting point, quartz with low melting point, a glass optical fiber and the like. By adopting the medium with low melting point as the fusion medium, the method can finish fusion under the condition that the temperature is far lower than the melting point of the optical fiber without causing slight deformation of a fiber core structure of the optical fiber, thereby increasing the coupling efficiency of signal light.

Description

technical field [0001] The invention relates to a novel optical fiber side coupler, which is suitable for all-fiber high-power / energy optical fiber lasers and optical fiber amplifiers, and belongs to the technical field of lasers. Background technique [0002] In high-power fiber lasers and fiber amplifiers, the pump coupling technology is the core technology. The purpose is to couple tens of watts or even hundreds of watts of LD pump light power into the inner cladding of double-clad fibers with a diameter of only hundreds of microns. , to obtain high pump power. As an important pumping method, side-pump coupling makes good use of the characteristics of double-clad fibers. Among them, the optical fiber angle grinding and polishing coupling technology refers to the technology of grinding and polishing the end face of the pump fiber at an angle (inclined), and then coupling the end face with the side of the double-clad fiber. This technology has the characteristics of high ...

AI Technical Summary

Problems solved by technology

However, the optical glue commonly used in this technology will fail and ablate due to heat under high pump optical power injection, resulting in the inoperability of the side coupler

[0003] In this regard, Ou Pan et al. proposed the use of CO 2 The method of making a fusion-bonded side coupler with a laser, and carried out experimental research, to a certain extent solved the problem that the angle grinding-polishing coupling technology cannot withstand high pumping optical power density

However, in the fusion splicing process, the contact surfaces of the two coupled optical fibers need to be melted, and the softening temperature of fused silica is above 1700°C. The high temperature during the production process and the large fusion splicing area will destroy the double cladding to a certain extent. The structure of the double-clad fiber, especially the core structure and size of the double-clad fiber, will affect the coupling efficiency of the pump light and the transmission of the core beam, thereby affecting the beam quality of the output light.

During high-power operation, due to the leakage of the core laser power, the efficiency of the fiber laser will be affected, and the fiber will even be burned

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