Abstract
In this thesis, we propose and experimentally demonstrate an all optical PSK format conversion in a bi-directional scheme using four-wave mixing (FWM) effect in highly nonlinear fiber (HNLF). In the FWM process, a 20-Gbits/s quadrature phase-shift keying (QPSK) signal and a continuous wave (CW) are utilized as pumping light and probe light, respectively. A 10-Gbits/s binary phase-shift keying (BPSK) signal, which is the idler light, is successfully obtained with optical signal-to-noise ratio (OSNR) about 25 dB and bit-error rate (BER) lower than 10-4 . Similarly, a 10-Gbits/s 45°PSK signal is used as pumping light and a 10-Gbits/s BPSK signal is used as probe light. After FWM process in a HNLF, a 20-Gbits/s QPSK signal, which is the idler light, can be obtained with OSNR about 30 dB and BER lower than 10-4 .