Low-cost lateral force sensor based on a core-offset multimode fiber interferometer with intensity based interrogation technique

A novel lateral force sensor based on a core-offset multimode fiber interferometer with intensity-based interrogation technique is reported. An offset between the cores of the single-mode fiber and multimode fiber is made to produce high extinction ratio. When a lateral force is applied to a short section of the multimode fiber, the extinction ratio decreases with the interference phase almost unchanged. In addition to serving as a sensing head, the multimode fiber can also act as a filter to realize lateral force measurement by determining the power change from a power meter. Experimental results show that the power ratio change has a linear relationship with respect to the applied lateral force, and the resolution of the sensor configuration is about 0.01 N.