Characterization of picosecond pulse nonlinear propagation in chalcogenide As2S3 fiber

We characterize the nonlinear propagation of picosecond pulses in chalcogenide As2S3 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 As2Se3 fiber, we find that the As2S3 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(-1) in a 205 mm length of As2S3 single-mode fiber. The Raman gain coefficient is estimated to be 4.3 x 10(-12) m/W and the threshold pump peak power is estimated to be 16.2W for the 205 mm As2S3 fiber. We also demonstrate that we can infer the dispersion of the As2S3 fiber and justify the Raman response function by comparing simulation and experimental results. (C) 2009 Optical Society of America