Optical fiber sensor and optical fiber sensor system

An optical fiber sensor system comprising:

• an optical fiber sensor including:
• an optical fiber configured to change a polarization state of a propagating light when at least one of a vibration and a displacement occurs;
• a first optical transmitter arranged at one end of the optical fiber and configured to input a first wavelength light to the optical fiber;
• a first optical receiver arranged at other end of the optical fiber and configured to receive the first wavelength light propagated through the optical fiber in a first direction from the one end toward the other end;
• a first polarization fluctuation detector configured to detect a fluctuation of a polarization of a light received by the first optical receiver;
• a second optical transmitter arranged at the other end of the optical fiber and configured to input a second wavelength light to the optical fiber;
• a second optical receiver arranged at the one end of the optical fiber and configured to receive the second wavelength light propagated through the optical fiber in a second direction opposite to the first direction;
• a second polarization fluctuation detector configured to detect a fluctuation of a polarization of a light received by the second optical receiver;
• a first separator arranged between the one end of the optical fiber and the first optical transmitter and the second optical receiver, and configured to input the first wavelength light output from the first optical transmitter to the optical fiber and to cause the second optical receiver to receive the second wavelength light propagated through the optical fiber in the second direction;
• and
• a second separator arranged between the other end of the optical fiber and the second optical transmitter and the first optical receiver, and configured to input the second wavelength light output from the second optical transmitter to the optical fiber and to cause the first optical receiver to receive the first wavelength light propagated through the optical fiber in the first direction, and
• a data processing device configured to collect a first polarization fluctuation data indicating a fluctuation of a polarization detected in the first polarization fluctuation detector and a second polarization fluctuation data indicating a fluctuation of a polarization detected in the second polarization fluctuation detector.