Wire drawing equipment and method for large-core-diameter single-polarization optical fiber

Abstract

The invention relates to a wire drawing device and method for a large-core-diameter single-polarization optical fiber. The equipment is characterized by comprising wire drawing furnace low-temperatureareas, wire drawing furnace high-temperature areas and an annealing pipe, wherein the wire drawing furnace low-temperature areas and the wire drawing furnace high-temperature areas are alternately and sequentially arranged to form a heating furnace area, the center lines of the two wire drawing furnace high-temperature areas are perpendicular to the center connecting line of stress elements of the optical fiber, the center lines of the two wire drawing furnace low-temperature areas are consistent with the center connecting line of the stress elements, and the annealing pipe is placed under the center line of the furnace area. The method is characterized by comprising the following steps: 1, clamping a preform in the wire drawing furnace; 2, heating the wire drawing furnace; 3, loading thepreform on a disc, and setting the temperature of the annealing pipe; 4, subjecting the preform to vacuumizing treatment; step 5, carrying out wire drawing; and 6, cutting off the optical fiber. Non-uniform internal stress generated in the wire drawing process of the large-core-diameter single-polarization optical fiber can be eliminated, so the optical fiber has the characteristic of complete welding after being cut, and the usability of the optical fiber is thus realized.

Description

technical field [0001] The invention relates to the field of optical fiber technology, in particular to a large-core-diameter single-polarization optical fiber drawing device and method. Background technique [0002] Ordinary optical fibers are designed with a symmetrical cylindrical structure, but in practical applications, they will also become asymmetrical due to mechanical stress, resulting in birefringence, so the polarization state of light will change irregularly when transmitted in ordinary optical fibers. The main influencing factors are wavelength, curvature, temperature and so on. Polarization-maintaining fiber can solve the problem of polarization state change. Usually, a panda-shaped or bow-tie-shaped stress circle is used to apply stress to the fiber core to generate stress-induced polarization, thus becoming a polarization-maintaining fiber or a single polarization fiber. [0003] The traditional drawing method of polarization-maintaining optical fiber is to ...

AI Technical Summary

Problems solved by technology

However, this wire drawing process mainly has two defects. One is that the shape of the preform is not uniform due to the existence of stress elements. The element is mainly composed of boron-doped quartz with a low melting point, and the heating of the annular heating furnace not only wastes energy consumption but also is unfavorable for optimizing the uniformity of the quartz and the stress element; , Insufficient duration, resulting in uneven residual stress inside the optical fiber

Optical fibers with uneven internal stress or structural defects will cause excessive warping of the optical fiber and cracks on the end face during cutting, which will lead to loss of use of the optical fiber

Especially for polarization-maintaining fibers or single-polarization fibers with a cladding diameter of about 400 μm, the conventional drawing process of polarization-maintaining fibers will cause almost 100% of the fibers to have end-face cracks after cutting, resulting in many bubbles during fusion splicing and transmission of tens of watts Even when the laser power is even lower, the loss and heat are very large, and it is easy to burn out, so it can withstand power of more than one hundred watts, and the mechanical tensile strength and bending resistance of the optical fiber are usually very low, which loses its usability

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