Fiber gratings have been used to measure strain fields in pressure vessels made of composite materials and aircraft adhesive joints1 . Measuring transverse loads have traditionally been performed by inducing a differential strain across the optical core of a fiber. Small changes in load cause the birefringence in the fiber to increase and capturing the spectral shifts using this method necessitates extremely accurate readout systems and careful analysis. This paper suggests a new approach for measuring transverse load by converting it to longitudinal strain and covers a very high-speed system used for measuring velocity, position, and pressure events that are on the order of a few microseconds.
"Force and pressure sensing using fiber grating sensors", Proc. SPIE 10208, Fiber Optic Sensors and Applications XIV, 102080Q (27 April 2017); doi: 10.1117/12.2261450; https://doi.org/10.1117/12.2261450