Photodarkening-resistant ytterbium-doped quartz optical fiber and preparation method therefor

A preparation method for a photodarkening-resistant ytterbium-doped silica optical fiber, wherein, the preparation method at least includes:

• applying a sol-gel method and an immersion method to an improved chemical vapor deposition method to prepare a ytterbium-aluminum-phosphorus-doped silica soot body, and then after dehydration, decarburization, collapse, and drawing, a photodarkening-resistant silica optical fiber is finally prepared, wherein a silica transparent sol solution is obtained by at least the following step
• S1:
• first weighing an ytterbium source, aluminum source, and phosphoric acid according to preset molar percentages, then preparing a mixed solution of ethyl orthosilicate, water, and ethanol, and finally adding the ytterbium source, aluminum source, and phosphoric acid in sequence into the mixed solution, and after the mixed solution is fully mixed, the silica transparent sol solution can be obtained,
• wherein preparing the ytterbium-aluminum-phosphorus-doped silica soot body comprises the following steps:
• S2:
• Polishing, injecting sulfur hexafluoride and oxygen into a deposition tube, then heating the deposition tube to 2000° C., and chemically polishing the inner wall of the deposition tube;
• S3:
• Depositing, injecting silicon tetrachloride and oxygen to the polished deposition tube, heating the deposition tube to 1400-1600° C., and depositing silica soot body;
• S4:
• Soaking, immersing part of the deposition tube in the silica transparent sol solution described in step S1 to obtain the ytterbium-aluminum-phosphorus-doped silica soot body.