Cladded pumping optical fiber capable of efficiently adsorbing pumping light

Abstract

The invention discloses a cladded pumping optical fiber capable of efficiently adsorbing pumping light and belongs to the field of manufacturing of a special optical fiber. The optical fiber comprises a fiber core, an inner cladding layer and an outer cladding layer from inside to outside sequentially, wherein the refractive index of the inner cladding layer is gradually reduced from the direction of the fiber core to the direction of the outer cladding layer; the refractive index of the fiber core is more than the maximum refractive index of the inner cladding layer; the refractive index of the outer cladding layer is less than the minimum refractive index of the inner cladding layer; and the section of the inner cladding layer is in a round shape. By the cladded pumping optical fiber, the problems of difficulty of the double cladding layer optical fiber with a step refractive index profile circle symmetric inner cladding layer structure in pumping adsorption and high splicing loss, low flexibility and the like of the double cladding layer optical fiber with a non-circle symmetric inner cladding layer structure are solved. In the invention, a rare-earth doped optical fiber has the characteristics of high pumping adsorption, low splicing loss, high flexibility and the like, is easy to manufacture and is very suitable for manufacturing a high-power pumping coupling optical fiber laser and a high-power pumping coupling optical fiber amplifier with high cost performances.

Description

technical field [0001] The invention belongs to the field of special optical fiber manufacturing, and relates to a double-clad rare-earth-doped optical fiber structure for high-power optical fiber lasers and optical fiber amplifiers that absorbs pump light with high efficiency. Background technique [0002] Since the birth of rare earth-doped fiber lasers and fiber amplifiers, they have been widely used in many fields such as communication, medical treatment, sensing and military due to their advantages of high efficiency, simplicity, stability and strong compatibility. Early rare-earth doped fiber lasers and fiber amplifiers mostly used a single-cladding structure, and the pump light and lasing laser propagated together in the doped fiber core, that is, the fiber core pumping mode. In this mode, the fiber core is a single-mode type , the core diameter is very small (usually no more than 10 μm), so this type of fiber laser has better beam quality. However, under fiber core ...

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Problems solved by technology

[0004] The purpose of the present invention is to overcome the difficulties in pump absorption of the existing circularly symmetrical inner cladding structure double-clad optical fiber and the problems of high splicing loss and low flexibility of the non-circularly symmetrical inner cladding structure double-clad optical fiber, etc., to provide a It has high pump absorption efficiency and good splicing characteristics. At the same time, the technical requirements are relatively simple, which is convenient for the production of rare earth-doped double-clad fibers for high-power fiber lasers and fiber amplifiers.

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