Several optical effects can degrade the signal quality of optical transmission over silica glass fiber. The more well-known mechanisms, such as attenuation and chromatic dispersion, are linear in nature and can be accurately predicted. Other mechanisms that affect signal quality cannot be readily predicted because their response is nonlinear. As telecommunications and other optical fiber applications increase their performance requirements, these "nonlinear optical effects" are gaining significance. Nonlinear effects can be grouped into two general categories: stimulated scattering effects related to signal strength; and modulation effects related to the optical intensity of the transmitted signal. This article focuses on one of the nonlinear scattering effects, stimulated Brillouin scattering.