A random-rotational angle fiber sensor

This paper has successfully achieved a new type optomechanical rotational angle sensor which consists of two FBGs glued axially on a capillary surface that is driven bent by attraction of a magnetic disk. Whenever an input force exerts on the end of this sensor, these two FBGs undergo strain caused by shaft rotation and result in their central wavelength shifts respectively. This sensor can be used to accurately detect random rotation angle in both static and dynamic conditions except the maximum deviation of 0.876 deg from 195 deg. The excellent sensor characteristics including linear response, fine resolution, negligible hysteresis, and long-term stability are experimentally demonstrated.