Nonlinear long-period gratings in As2Se3 chalcogenide fiber for all-optical switching

We present experimental demonstration of all-optical switching using long-period gratings (LPGs) in highly nonlinear As2Se3 chalcogenide fiber. We use a 135 mm grating which is generated using acoustic waves. We characterize the nonlinear pulse propagation through the LPG using picosecond pulses tuned to different wavelengths with respect to the grating resonance. We compare the results with numerical simulations and observe switching at pulse peak powers around 50 W, two orders of magnitude smaller than previously demonstrated in silica. (C) 2008 American Institute of Physics.