Acoustic sensitivity predictions of single-mode optical fibers using Brillouin scattering

Elastic and elastooptic coefficients used to predict acoustic response sensitivity for two single-mode optical fibers have been determined from Brillouin scattering measurements. These measurements were made on two ITT single-mode fiber preforms currently of interest in the fabrication of fiber-optic acoustic sensors. Previous predictions of acoustic sensitivity assumed the optical fiber waveguides as homogeneous fused silica cylinders. It was found that this assumption introduces no more than a 5% error in the pressure sensitivity for a low numerical aperture (N.A.) fiber and a 30% error for a high N.A. fiber.