Solid-core polarization-maintaining cut-off-free single-mode microstructure optical fiber and preparation process thereof

Abstract

The invention discloses a solid-core polarization-maintaining cut-off-free single-mode microstructure optical fiber and a preparation process thereof. The solid-core polarization-maintaining cut-off-free single-mode microstructure optical fiber comprises an outer cladding layer of an annular solid structure, an inner cladding layer with periodically distributed air holes and a solid fiber core positioned in the geometric center of the optical fiber which are sequentially distributed from outside to inside, wherein the inner cladding comprises a plurality of circles of air holes; central connecting lines of each circle of air holes in the radial section form a regular hexagon; one of the air holes in the innermost ring or two or three continuous air holes which are symmetrically distributedis/are defined as a first air hole or first air holes; the rest air holes are defined as second air holes, the hole diameter of the first air hole/holes is smaller than that of the second air holes,and a ratio of the hole diameter of the second air holes to a distance between the centers of every two adjacent air holes is smaller than 0.42. The solid-core polarization-maintaining cut-off-free single-mode microstructure optical fiber has advantages that the optical fiber supports a cut-off-free single mode, has a large mode field area, is adjustable in dispersion, can transmit polarized lightand birefringence, is simple in preparation, does not need to be doped with a silicate glass stress rod, can maintain an optical fiber microstructure, is low in preparation cost, and is high in preparation yield.

Description

technical field [0001] The invention relates to an optical fiber and its preparation technology, in particular to a solid-core polarization-maintaining non-stop single-mode microstructure optical fiber and its preparation technology. Background technique [0002] As a kind of special optical fiber, polarization maintaining fiber, as the name implies, can transmit linearly polarized light and keep the polarization state of the light unchanged or rarely changed during transmission. Polarization maintaining optical fiber is widely used in aerospace, industrial manufacturing, unmanned driving, communication and other fields. There are two ways to realize the polarization maintenance of optical fibers: one way is to add stress regions symmetrically on both sides of the fiber core (for example, borosilicate glass is used as the material of the stress region), and the birefringence of the fiber core is improved based on the internal stress to achieve Polarization effect, such comm...

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Problems solved by technology

And so far, there is no suitable solution

Although NKT abroad proposed to add stress regions at both ends of the fiber microstructure to achieve large mode field and no cut-off single-mode polarization maintaining, this method is only a simple combination of ordinary polarization maintaining fiber (such as panda fiber) and photonic crystal fiber. Combination, the preparation of optical fiber is very difficult, and because silicate glass needs to be used in the stress zone, its glass transition temperature and drawing temperature are much lower than that of pure silica glass, making it extremely difficult to maintain the microstructure of the optical fiber during the drawing process, so this method does not not widely adopted

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