Yb-doped fiber and manufacturing method thereof

Abstract

The invention discloses an Yb-doped fiber and a manufacturing method thereof. The Yb-doped fiber comprises a core layer at least containing Yb and Al, a glass matrix cladding surrounding the core layer, and a low-refractive index coating layer surrounding the glass matrix cladding. The glass matrix cladding comprises an inner cladding and an outer cladding. The refractive index of the inner cladding is lower than that of the core layer, and higher than that of the outer cladding. The inner cladding uses Ge, P, Al, and F as doping agents. The core layer is doped with F and P as doping agents. A MCVD method is used to manufacture a performing bar, fiber-drawing temperature is controlled, so optical fibers are drawn under relatively low tension, and required fibers are obtained. Through improving the refractive index of the inner cladding, relatively through reducing the difference between the refractive index of the core layer and the refractive index of the inner cladding, relatively high Al and Yb doping concentration in a fiber core is maintained, so as to reduce core layer NA under the condition that relatively high fiber cladding absorption coefficient is maintained, and single-mode output is realized, that is, fiber quality factor is proximity to one. The manufacturing method can manufacture a high-concentration Yb-doped fiber, and realizes relatively high cladding absorption coefficient.

Description

technical field [0001] The invention belongs to the technical field of optical fiber manufacturing, and more specifically relates to an ytterbium-doped optical fiber and a preparation method thereof. Background technique [0002] Rare earth-doped fibers are formed by adding rare earth elements to the core region of the optical fiber, which has the function of optical amplification and can be applied to light sources such as lasers and optical amplifiers and transmission systems. Among them, the fiber laser made of fiber containing rare earth element ytterbium (Yb), that is, ytterbium-doped fiber, has good beam quality and can obtain high-power output light, and the oscillation wavelength of the output light of the fiber laser is different from that of existing high-power lasers. A Nd-YAG laser is basically the same, around 1μm. Therefore, Yb-doped lasers inherit the material processing purposes of traditional lasers such as welding, marking, and cutting. [0003] The proce...

AI Technical Summary

Problems solved by technology

If a large amount of phosphorus pentoxide is doped, because phosphorus pentoxide volatilizes severely at high temperature, it is easy to form a central depression in the refractive index profile and a shift in the actual refractive index of the optical fiber during the process of making the preform.

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