A novel all-optical clock recovery scheme

We experimentally demonstrate all-optical clock recovery (CR) from the nonreturn-to-zero (NRZ) data without any preprocess measure. Multi-quantum-well (MQW) Fabry-Pérot semiconductor optical amplifier (FP-SOA) acts as dual role including both data format converter and clock recovery device. To achieve amplitude equalization of recovered clock pulses, a self-nonlinear polarization switching (SNPS) including the FP-SOA, two polarization controllers (PCs) and one polarization beam splitter (PBS) is employed. Using the presented scheme, stable and low jitter 35.80 GHz optical clock pulses were directly extracted out from input NRZ data. This scheme has some distinct advantages such as being transparent to data format, free preprocess, free pre-amplification, convenient tuning, good tolerance to long “0s” data, and good tolerance to wavelength drifting of input data.