[Study on temperature character of stimulated Raman scattering spectrum in silica fiber]

Stimulated Raman scattering (SRS) spectrum of silica fiber was studied under different temperatures. The influence of temperature on feature of SRS spectra was analyzed theoretically and experimentally. The laws of how the Raman frequency-shift, bandwidth and intensity of the first order Stokes light change with the temperature were obtained using a pulsed Q-switched doubled frequency laser. The experiments indicate that the frequency-shift becomes bigger with the increasing the temperature. Raman frequency-shift has a linear relationship with the temperature. Under the same pump power, when the temperature is lower, the order of SRS spectrum is lower. Lower temperature has high order Stokes light. For higher order Stokes lights, the lower the temperature, the higher the threshold. But the changes in spectrum bandwidth show no linear relationship with the temperature, and there is a maximum of bandwidth. Theory and experiments indicate that temperature has direct effect on the SRS of fiber.