针对标准单模石英光纤磁光特性弱的特点，利用改进化学气相沉积（modifiedchemical vapor deposition，MCVD）法结合原子层沉积（atomic layer deposition，ALD）技术制备了Bi/Er/La共掺有源光纤，并且用伽马射线辐照对该光纤进一步处理；搭建了光纤的费尔德常数测试系统，研究辐照前后Bi/Er/La共掺有源光纤的磁光特性。实验结果表明：在波长为1 310 nm处，Bi/Er/La共掺有源光纤的费尔德常数（1.02 rad/（T · m））比单模光纤（0.76 rad/（T · m））高约36.2%。经伽马射线辐照后，Bi/Er/La共掺有源光纤的费尔德常数随着辐照剂量的增加而增大，经3.0 kGy剂量处理后，其费尔德常数增加了54.90%，而单模光纤的费尔德常数仅增加了26.3%，且在1.0 kGy辐照处理已达到饱和。
To improve the weak magneto-optical properties of standard single-mode fibers, in this paper, we fabricated a Bi/Er/La co-doped active silica fiber by using modified chemical vapor deposition (MCVD) method in combination with atomic layer deposition (ALD) technology. Furthermore, we processed the fiber with gamma-ray irradiation. A Verdet constant measurement system for fibers was built to study the magneto-optical properties of Bi/Er/La co-doped active silica fiber before and after irradiation. Experimental results show that the Verdet constant of Bi/Er/La co-doped active silica fiber is 1.02 rad/(T · m)at 1 310 nm, which is 36.2% higher than that of standard single-mode fiber. It is also shown that the processing of gamma-ray irradiation can improve the magneto-optical property of the fiber, and the Verdet constant of Bi/Er/La co-doped active silica fiber increases with the increase of irradiation dose. Especially under the irradiation dose of 3.0 kGy, the Verdet constant increases by 54.90%, whereas that of standard single-mode fibers increases only by 26.3% and gets saturation at the irradiation dose of 1.0 kGy.
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