The effects of hydrostatic pressure on forward-stimulated Brillouin scattering in telecom optical fibers

Abstract A detailed experimental study on the effect of hydrostatic pressure on forward stimulated Brillouin scattering (FSBS) in telecommunications optical fibers is presented. The response of radial and torsional-radial guided acoustic modes is described. Specifically, the change in their resonance frequency and the variation in linewidth in response to external pressure changes were studied. A different response was found for shear-like and dilatational-like guided acoustic modes. A simplified theoretical model incorporating the dominant contributions is proposed to describe the pressure response, providing a good description of the experimental results. The results presented support the development of different strategies for FSBS-based fiber optic pressure sensors. Furthermore, we demonstrate that the properties of shear-type torsional-radial modes enable FSBS-based pressure monitoring in liquids.