Novel fiber grating sensing technique based on the torsion beam

A novel fiber grating sensing technology based on the torsion beam is reported for the first time. The Bragg wavelength change is linear with the torsional angle and the torque. The fiber Bragg grating (FBG) is firmly mounted on the surface of the torsion beam with a determinate angle along the direction of the axes of the torsion beam. The range of the torsional angle is between -45 degree(s) and +45 degree(s). The sensing sensitivity of the torsional angle is up to 11.534 degree/nm and that of the torque is up to 0.1595 Nm/nm, respectively. The formulas have been derived theoretically and the experimental results basically accord with the theoretical ones. This technology has many advantages, such as two dimensional tuning, the high sensitivity, the good repetitiveness and no chirping for the torsional angle within the range -45 degree(s) and +45 degree(s), etc. It has potential applications in the area of the fiber sensing, the fiber communication and laser technology.