| 摘要 |
PROBLEM TO BE SOLVED: To provide a low cost optical fiber vibration sensor that has high detection sensitivity, can accurately detect a location to which vibration is applied, and allows for a longer distance to a vibration detection object.SOLUTION: The optical fiber vibration sensor comprises: two optical fibers 2 with the same length; a light source 3; an optical receiver 4; a coupler 5 that splits pulse light coming from the light source 3 and radiates the light into the two optical fibers 2, and couples scattered light generated when the pulse light propagates through the optical fiber 2 to output the scattered light as interference light to the optical receiver 4; and a signal processing circuit 6 that detects light intensity of the interference light from the output of the optical receiver 4, and detects vibration from variations in the light intensity of the interference light when the vibration is applied to both or one of the two optical fibers 2. The signal processing circuit 6 detects: vibration intensity by using the magnitude of variations in light intensity of the interference light; and a location on the optical fiber 2 to which vibration is applied, from a time period from the time when the pulse light is radiated to the time when light intensity of the interference light varies. |
