All-fiber optical switch based on Raman scattering

We demonstrate for the first time to our knowledge a nonlinear optical switch based on the Raman effect in a Sagnac loop with highly GeO/sub 2/ doped fiber. In addition to providing all-optical switching, this device also amplifies the signal pulse. Because the Raman amplification dominates over the Kerr effect in highly-germanium-doped fibers, the transfer function of this switch exhibits a behavior different to that of the purely Kerr switch.