All optical format conversion at 10 Gbps using SOA and optical band-pass filter

In this paper, an all-optical non return-to-zero (NRZ) and return-to-zero (RZ) modulation format converter using a single semiconductor optical amplifier (SOA) and an optical band-pass filter (OBPF) is proposed. The format converter consists of a single SOA which is acting as a nonlinear element to broaden the spectrum of the input signal and the OBPF which is used to extract the special spectrum from the broadened spectrum. By adopting the ultra-fast SOA model associated with optical system software, the 10 Gbps NRZ and RZ format conversion is successfully demonstrated with simulation. We also demonstrate the proof-of-principle experiment at 10 Gbps by using the test SOA and OBF converter. The converted NRZ is achieved with an output extinction ratio of 11.51 dB. The BER is 5.5 10-9 while the power of NRZ is -10 dBm and the BER is 1.0 10-9 when the power of RZ is -14 dBm. The experimental results coincide well with the simulated results. The proposed scheme is robust and has potential for applications in future optical networks.