Single-Fiber Sagnac-Like Interferometer for Optical Rotation Measurement in Atomic Spin Precession Detection

In this paper, a single-fiber Sagnac-like interferometer is proposed and experimentally demonstrated for detecting atomic spin precession in an atomic magnetometer. The single-fiber Sagnac-like interferometer has a reciprocal optical structure, which is insensitive to environmental disturbances. The fiber system is more flexible for implementation in miniature atomic magnetometers, which has potential for application in magnetoencephalography systems. The sensitivity and the bandwidth of the system are also discussed. The thermal and bending disturbances to fiber system are observed, whereas the long-term stability is analyzed and compared with the Faraday modulation scheme.