基于光纤Sagnac干涉结构的磁光光纤费尔德常数测量

摘要

提出了一种基于光纤 Sagnac 干涉结构的磁光光纤费尔德(Verdet)常数测量方法。通过测量光纤Sagnac干涉结构的损耗及其所能达到的最小透射率，可计算光路中耦合器的分光比；进而根据Sagnac干涉结构的透射率随外加磁场的变化，确定光纤的等效Verdet常数值。使用该方法实验测量了高非线性光纤Verdet常数的波长依赖性，成为磁光四波混频效应研究中磁光耦合系数选择和波长设置的重要依据。%A method was presented to measure Verdet constant for magneto-optical fibers based on Sagnac interferometer. The power-split ratio of the fiber coupler used in Sagnac interferometer can be calculated from fiber loss and minimum transmittivity available, and then effective Verdet constant is determined by magnetic field dependence of the transmittivity for Sagnac interferometer. By means of this method, the wavelength dependency of Verdet constant for a highly nonlinear fiber was also measured, which is extremely useful for the study of magneto-optical four wave mixing associated with magneto-optical coupling coefficient and operating wavelength.