Brillouin bandwidth determination from excess-noise characteristics of SBS signals in single-mode fibers

The effects of stimulated Brillouin scattering (SBS) on the power-handling capability of single-mode optical fibers has been extensively studied in recent years.12 In low-loss silica fibers in the 1.3- and 1.5-µm telecommunications windows, thresholds for the onset of SBS as low as a few milliwatts have been reported. The SBS frequency offset and bandwidth have been investigated for a variety of different fibers3,4; Brillouin gain bandwidths ranging from ~30 to ~200 MHz have been reported at 1.3 µm, compared to the 21-MHz bandwidth for bulk silica. In this paper we show that SBS bandwidths determined from direct heterodyne detection correlate with the bandwidth determined from the excess intensity noise of the SBS signal.