Characterization of picosecond pulse nonlinear propagation in chalcogenide [As.sub.2][S.sub.3] fiber

We characterize the nonlinear propagation of picosecond pulses in chalcogenide [As.sub.2][S.sub.3] single-mode fiber using a pump-probe technique. The cross-phase modulation (XPM)-induced sideband broadening and stimulated Raman scattering (SRS)-induced sideband amplification are measured in order to map out the Raman gain spectrum of this glass across the C-band. We extract the Raman response function from the Raman gain spectrum and determine the power and polarization dependence of the SRS. In contrast to previous work using [As.sub.2][Se.sub.3] fiber, we find that the [As.sub.2][S.sub.3] fiber does not suffer from large two-photon absorption (TPA) in the wavelength range of the telecommunications band. We achieved a 20 dB peak Raman gain at a Stokes shift of 350 [cm.sup.-1] in a 205 mm length of [As.sub.2][S.sub.3] single-mode fiber. The Raman gain coefficient is estimated to be 4.3 x [10.sup.-12] m/W and the threshold pump peak power is estimated to be 16.2 W for the 205 mm [As.sub.2][S.sub.3] fiber. We also demonstrate that we can infer the dispersion of the [As.sub.2][S.sub.3] fiber and justify the Raman response function by comparing simulation and experimental results. [c] 2009 Optical Society of America OCIS codes: 060.0060, 060.4370, 190.0190, 190.4370.