DPSK receiver-sensitivity enhancement using an SOA in front of the receiver
A technique for DPSK receiver-sensitivity improvement is demonstrated using numerical simulations. It is based on reshaping and reamplifying of received 80 Gbit/s DPSK using an SOA before a one bit delay interferometer. The SOA re-amplifies data without adding amplitude or differential phase noise due to its gain-compression. The system is tested using 231-1 PRBS RZ-DPSK (NRZ-DPSK) loaded with both phase and amplitude noise. It shows 2dB (1.7dB) quality-factor improvement. The estimated BER by error-counting shows receiver-sensitivity improvement of ≅3dB in case of single-ended detection and ≅2dB (≅2.5dB) in case of balanced-detection. This single-ended improvement is comparable to that of common DPSK balanced-detection technique. © 2010 COPYRIGHT SPIE - The International Society for Optical Engineering.