Fiber metrology and point sensing based on forward-stimulated Brillouin scattering

Coupling between mechanical oscillations and optical resonances has demonstrated to be a powerful approach to investigate forward-stimulated Brillouin scattering (FSBS) in optical fibers leading to new applications. Long-period fiber gratings and whispering-gallery mode resonances permit to probe acoustic modes with high sensitivity, enabling the development of point sensors based on FSBS. Applying these concepts, Poisson’s ratio of the optical fiber and fiber diameter were measured with unprecedented precision. Simultaneous and discriminative measurements of strain and temperature were carried out with a single FSBS point sensor. The potential of FSBS as the physical mechanism to develop sensors based on the concept of mass-microbalance, suitable for bio-sensing applications, is explored.