摘要

An all-fiber magneto-optic Sagnac interferometer (AFMOSI) utilizing intrinsic Faraday effects in highly nonlinear fibers (HNLFs) is presented for the first time (to our knowledge). The performance of the AFMOSI was investigated theoretically by use of the transfer matrix approach. The theoretical results were verified by the experiment employing an all-fiber magnetic-optic cell that consists of a 30 m long HNLF and a 92 mm diameter toroid coil. Our experiments show that, when the linear birefringence of the AFMOSI is adjusted to 0, the change of the transmission can be over 10 dB as the magnetic induction B increases from 0 to 180 Gs. The sensitivity of the AFMOSI is determined by the coupling ratio of the fiber coupler, the loss of the loop, and the length of the HNLF. Most importantly, the linear birefringence of the AFMOSI can be obtained by evaluating its performance of magnetic field response. This is very useful for studying the influence of the linear birefringence on the performance of a nonlinear optical loop mirror that is controlled by the Faraday effect.