A double-clad ytterbium-doped optical fiber

Abstract

The invention discloses a double-clad ytterbium-doped fiber, and relates to the technical field of optical fibers. The fiber comprises, in order from the inside to the outside, a core, an inner cladding and an outer cladding; the core includes, from the inside to the outside, a circular central core region, and at least four annular doped core regions concentrically disposed with the central coreregion, wherein the concentrations of ytterbium ions of the central core region and the four annular doped core regions sequentially increases from inside to outside; and both the inner cladding and the outer cladding are quartz claddings. The double-clad ytterbium-doped fiber provided by the invention optimizes the power distribution of the ytterbium-doped fiber and improves the stable working capability under the condition of high-power fiber laser output.

Description

technical field [0001] The invention relates to the field of optical fiber technology, in particular to a double-clad ytterbium-doped optical fiber. Background technique [0002] Semiconductor lasers and fiber optic materials are two great inventions of the 20th century. The combination of the two directly promotes the development and industrial application of fiber optic communications and fiber lasers. Fiber laser is a technology developed on the basis of EDFA technology. As early as 1961, E.Snitzer of American Optical Company carried out pioneering work in the field of fiber laser, but due to the limitation of relevant conditions, the experimental progress was relatively slow . The low-loss erbium-doped fiber in the 1980s brought new prospects for fiber lasers. [0003] In recent years, with the successful development of double-clad ytterbium-doped fibers, fiber lasers with ytterbium-doped fibers as core components have begun to develop rapidly. With the continuous mat...

AI Technical Summary

Problems solved by technology

[0005] However, due to the quantum deficit caused by the laser transition in the ytterbium-doped fiber core, this ratio is within 10% of the pumped light energy. In addition, the non-radiative transition between energy levels and the background loss of the fiber will further increase the thermal load.

The heat deposition in the fiber core will make the temperature of the fiber increase with the increase of the pumping power, which may cause the aging or damage of the coating material

In addition, even if the shape of the quartz cladding is irregular, it is difficult to break all the helical light modes, so that part of the pumping light is still difficult to enter the fiber core, resulting in unnecessary transmission of high-power pumping light in the quartz cladding

These factors, as the power of the fiber laser reaches more than 1000 watts, when it enters the level of 3 kilowatts, 5 kilowatts or even 10,000 watts, these tiny factors that people did not pay much attention to in the past will have a major impact, resulting in the difficulty of stabilizing high-power lasers. work, even short-lived

Images