Stability-improved slow light in polarization-maintaining fiber based on polarization-managed stimulated Brillouin scattering

Abstract

With the idea of controlling the polarizations of the pump and Stokes beams in an optical fiber, a simple scheme is presented for enhancing the stability of the stimulated Brillouin scattering (SBS) interaction and thus that of the SBS-based slow light. For this purpose, a special slow-light element is constructed by fusing a polarization-maintaining circulator (its fast axis being blocked) to each terminal of the polarization-maintaining fiber (PMF). This configuration ensures that the pump and Stokes beams always have identical polarization in the whole fiber during the SBS interaction. An experimental setup is established accordingly. The SBS gain feature and the slow-light performance are studied. A tunable time delay with a slope of 0.82 ns dB−1 is demonstrated for a Gaussian pulse with a width of 88.9 ns. The experimental results with and without polarization management are compared. It is found that such a polarization-managed scheme can improve both the stability of the Brillouin gain and that of the time delay of the Stokes pulse. Moreover, for the same pump power, the Brillouin gain is also enhanced.