A large-mode-field bending-resistant single-mode fiber with parabolic cores coupled with lobe-shaped cores

Abstract

The invention discloses a parabolic core coupling segmented-cladding core large mode field bending-resistant single-mode fiber, and belongs to high-power fiber amplifiers, laser devices and special fibers. The center of the fiber is a rare earth ion doped core area (1), an inner clad layer (2), N segmented-cladding fiber cores (3, 1)...(3, N) and an outer clad layer (4) are distributed from insideto outside, the N segmented-cladding fiber cores are uniformly distributed around the rare earth ion doped core area (1) and are the same in radius and radian, the refractivity profile of the rare earth ion doped core area (1) is in a parabolic shape, maximum relative refractive index difference delta is (n1-n2), the refractive indexes n1 of the segmented-cladding fiber cores are equal, and the refractive index n2 of the inner clad layer (2) is lower than that of the segmented-cladding fiber cores. The maximum relative refractive index difference delta is of the parabolic core is larger than0.002, and the single-mode fiber is easily manufactured by a traditional method and solves the problems of poor bending property of a segmented-cladding fiber and high manufacturing difficulty of a parabolic fiber. The segmented-cladding fibers cores can be prepared from fiber preform, materials are saved, manufacture is facilitated, and the single-mode fiber is applicable to large-scale production.

Description

technical field [0001] The invention relates to a large-mode-field bending-resistant single-mode optical fiber with a parabolic core coupled to a lobe-shaped core, and 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 lasers have been widely used in optical fiber communication, industrial processing, medical treatment, military and other fields. In 2010, a continuous laser with 10kW power has been reported. 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 o...

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Problems solved by technology

[0012] In order to overcome the limitation of the numerical aperture of the existing traditional optical fiber, the limited optical power of the single-core multi-doped rare earth ion region double-clad optical fiber, the difficulty of making the air hole of the photonic crystal fiber, and the low mass production yield of the single-mode multi-core optical fiber with large mode field, Due to the limited diameter of the core layer of the petal-shaped fiber, the bending sensitivity of the multi-groove fiber, and the difficulty in manufacturing the parabolic fiber, a large mode field bending-resistant single-mode fiber with a parabolic core coupled to the petal core is proposed.

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