A bending-resistant lobe-shaped large-mode-field single-mode fiber

Abstract

The invention, which belongs to the high-power fiber amplifier, laser, and special fiber fields, relates to an anti-bending lobe-shaped large-mode-field single-mode fiber. A rare-earth-doped ion core zone (1) is arranged at the center of the fiber; and N lobe-shaped fiber cores from (2,1) to (2,N) that have the same radiuses, same radians, and same thicknesses and are distributed uniformly around the rare-earth-doped ion core zone (1), an inner cladding layer (3), and an outer cladding layer (4) are distributed from inside to outside, wherein the N is an integer that is larger than or equal to 1 and is less than or equal to 8. The refractive index profile of the rare-earth-doped ion core zone (1) is in a parabola shape; a maximum relative refractive index difference delta is obtained by the following formula: delta= (n1-n2); the refractive indexes of the lobe-shaped fiber cores from (2,1) to (2,N) are equal and are n1; the refractive index, being n2, of the inner cladding layer (3) is less than the refractive indexes of the lobe-shaped fiber cores from (2,1) to (2,N); and the refractive index of the outer cladding layer (4) is less than that of the inner cladding layer (3). With the fiber, the adverse effect caused by bending of the lobed fiber can be eliminated and the anti-bending performance of the fiber is improved; and the large effective mode field area and the single-mode characteristic are realized. The manufacturing method is simple, convenient, and effective and is suitable for large-scale production.

Description

technical field [0001] The invention relates to an anti-bending petal-shaped large-mode-field single-mode optical fiber, which belongs to the fields of high-power optical fiber amplifiers, lasers and special optical fibers. Background technique [0002] Rare earth-doped fiber amplifiers or lasers use ion fibers doped with rare earth elements (Nd, Sm, Ho, Er, Pr, Tm, Yb, etc.), and use the stimulated emission mechanism to achieve direct amplification of light. [0003] With its excellent performance and low price, fiber laser has been widely used in optical fiber communication, industrial processing, medical treatment, military and other fields. With the development of laser technology applications, material processing, space communication, laser radar, photoelectric countermeasures, laser weapons, etc., high-power, high-quality lasers are required, and the single-mode output power is required to reach MW or even GW levels. However, the double-clad rare-earth-doped fiber las...

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Problems solved by technology

[0007] In order to overcome the low mass production yield of the existing single-mode multi-core optical fiber with large mode field, the limited optical power of the single-core multi-doped rare earth ion region double-clad optical fiber, the bending sensitivity of the multi-groove optical fiber and the bending resistance of the segmented cladding optical fiber core layer Poor performance and other defects, a bending-resistant lobe-shaped large-mode field single-mode fiber is proposed

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