Method for reducing stimulated brillouin scattering in waveguide systems and devices

The method of the invention controls the acoustic waves to be guided away from the portion of the waveguide which guides the light. Thus, acoustic waves are guided into the cladding. A substantial reduction in the SBS effect is then realized in the core that guides light. The method of the invention is applicable to single clad optical waveguides, such as optical fibers, as well as dual clad optical fibers and other waveguides. A preferred dual clad (a.k.a. dual core) waveguide structure permits realization of a pump laser system having reduced SBS effect in the core used for guiding transmitted light to be pumped (amplified). A second core guides acoustic waves outside the core used for guiding transmitted light, and also guides pump light which amplifies the light transmitted in the core for light transmission. Pumping may also be assisted by cladding the second “pump” core with a cladding that is anti-guiding for light and guiding for acoustic waves.