40 Gb/s optical wavelength converter for NRZ-DPSK signal based on four wave mixing in semiconductor optical amplifier

We simulated, 40 Gb/s wavelength converter for non-return to zero differential phase shift keying (NRZ-DPSK) signal using four wave mixing in semiconductor optical amplifier (SOA), for the first time. Also optimize the signal-to-pump ratio for NRZ-DPSK. The optimum signal-to-pump ratio is 12 dB & 10 dB with Q-factor penalty of 0.685 dB & 0.663 dB. The dependence of four wave mixing efficiency and converted signal power with signal input power studied & it is evaluated that four wave mixing efficiency decrease with increase in input power. The impact of pump power, signal-to-pump ratio, SOA parameters with Q-factor penalty for 40 Gb/s has been illustrated. We show that converted signal power increase up to saturation power of semiconductor optical amplifier, then decreases. It is observed that for optimum pump power, OSNR varies small with signal input power. Investigation also made for transmission distance after conversion.