Distributed bidirectional polarization measurement device based on double-beat-frequency single auxiliary interferometer

The invention provides a distributed bidirectional polarization measurement device based on a double-beat-frequency single auxiliary interferometer, and belongs to the field of optical fiber measurement. The device comprises a tunable laser source, an optical frequency domain interference reflection measurement module, an optical frequency domain interference transmission measurement module, a to-be-measured device module, an auxiliary interferometer module and a signal processing module, and is characterized by further comprising a signal filtering module and an extended optical fiber module. Continuous light output by the tunable laser source is injected as inquiry light into the to-be-measured device module, Rayleigh scattering light returns and is injected into the optical frequency domain interference reflection measurement module, polarization coupling light is injected into the optical frequency domain interference transmission measurement module, and after frequency sweeping nonlinearity is matched an