Waveguide-induced inhomogeneous spectral broadening of stimulated Brillouin scattering in optical fiber.

We provide direct experimental evidence of waveguide-induced inhomogeneous spectral broadening of stimulated Brillouin scattering (SBS) in optical fiber. It is shown that the SBS spectral width and gain depend on the numerical aperture for both single-mode and multimode fibers, the functional dependencies of which are in good agreement with our model description of the phenomenon.