| We experimentally demonstrate optical signal regeneration based on parametric amplification in dispersion-shifted fibers. An ultrafast, gain-flattened optical limiting amplifier is implemented to perform reshaping and reamplifying (2R regeneration) functionality of 20Gbit/s optical packets. The operating mechanism of the 2R limiting amplifier is based on ultrafast parametric-gain saturation due to pump depletion. Gain flattening is achieved by using two pieces of dispersion-shifted fiber that provide complementary gain spectra. The 3dB-bandwidth of this parametric amplifier is 15nm, which is a record to date to the best of our knowledge. By combining this optical limiting amplifier with a 10GHz phase-locked loop that performs retiming functionality, a 3R optical regenerator is implemented that effectively reduces timing jitter and amplitude noise. A wavelength-tunable all-optical clock recovery using a fiber-optic parametric oscillator is also implemented to demonstrate 100Gbit/s operation feasibility. The output clock wavelength can be tuned over the conventional EDFA bandwidth. This wavelength-tunable clock recovery is expected to be an important component in constructing wavelength converters with 3R regeneration functionality in optical cross-connect networks. |
