A preparation method of doped single crystal multi-core optical fiber and doped single crystal multi-core optical fiber

Abstract

The invention provides a doped monocrystal multi-core optical fiber and a preparation method thereof. According to the doped monocrystal multi-core optical fiber, two or more doped monocrystal fiber cores is arranged in the same silica cladded layer, and a low-refraction-index silicon dioxide quartz glass and high-refraction-index doped monocrystal form an optical fiber waveguide structure. The preparation method comprises the following steps: acquiring porous optical fiber preforming bars; drawing the porous optical fiber preforming bars to obtain porous capillary tubes; injecting doped crystal melt in micropores in the quartz capillary tubes at high temperature and under high pressure to form polycrystal fiber cores; and finally, carrying out transverse heating and enabling the fiber cores to be subjected to monocrystal treatment and the like to prepare the silica cladded doped monocrystal multi-core optical fiber. Capillary tube porous melt injection and later-period crystal growth are combined. The doped monocrystal multi-core optical fiber which grows by the method has the advantages of controllable wire diameter and length, optional number and arrangement of the fiber cores and the like. The doped monocrystal multi-core optical fiber can be used for miniature and online photon regulation and control phase modulators, optical switches, interferometers and the like.

Description

technical field [0001] The invention relates to an optical fiber, in particular to a doped single crystal multi-core optical fiber. The invention also relates to a method of manufacturing such an optical fiber. Background technique [0002] Single crystal optical fiber is also called crystal fiber or fiber crystal. It is a single crystal that grows crystal material into a fiber shape, with a diameter ranging from a few microns to hundreds of microns. It has both the functions of bulk crystals and ordinary silica fibers. Compared with bulk crystals, single crystal optical fibers have the characteristics of small size, high integration, and can be coupled with quartz optical fibers. It has the advantages of matching the lasers in the visible and non-visible bands, and can be used for the transmission of high-power lasers. It has important practical value in the field of optoelectronics. [0003] Ordinary pure single crystals have limited functions. In order to obtain the des...

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Problems solved by technology

The disadvantages of this optical fiber preparation method are: firstly, due to the surface electrostatic attraction, it is difficult to insert long-scale micro-single crystals into the micropores of the cladding sleeve; secondly, the large difference between the softening temperature point of quartz glass and the crystal melting point leads to In the process of stretching the cladding sleeve, the volatilization of the core melt occurs discontinuously or missing, and the quartz dissolves in the core melt, resulting in impurity pollution and hindering the crystallization process of the core melt, so that no single crystal can be formed; third, The stretching temperature gradient of the cladding sleeve is much higher than the temperature gradient force that promotes the nucleation and growth of the core melt to form a single crystal, which does not meet the kinetic conditions of single crystal growth

[0005] To sum up, the above-mentioned crystal fiber either has no cladding structure, or the core is difficult to guarantee to be a single crystal, and the fiber usually only contains a pure crystal core, which does not involve ion doping, so the prepared The function of the crystal fiber is limited, and it cannot meet the needs of further optical fiber sensing and new fiber integrated devices.

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