Stimulated Raman scattering of light in optical silica fiber under subnanosecond pumping

Stimulated Raman scattering (SRS) of light in a single-mode optical silica fiber under excitation by a subnanosecond laser pulse with a wavelength of 532 nm is studied. The dependence of the SRS power and its spectrum on the laser pumping power is investigated. It is shown that, at relatively low pumping powers, SRS is well described by an exponential function predicted by the model, neglecting pumping depletion. At powers causing deviations from this dependence, the SRS band, whose value depends on the pumping power, is additionally broadened. Features of the broadening are similar to that of a laser line in an optical fiber. Intense anti-Stokes scattering on vibrational modes over-populated because of the SRS process is also observed. © 2013 Allerton Press, Inc.