40 Gb/s NRZ-DQPSK Data All-Optical Wavelength Conversion Using Four Wave Mixing in a Bulk SOA

Differential quadrature phase shift keying (DQPSK) modulation has become particularly attractive in high-speed optical communications because of its resistance to fiber nonlinearities and its more efficient use of fiber bandwidth. Because of its wavelength conversion ability, semiconductor optical amplifier (SOA) four wave mixing effect has attracted much attention. We experimentally study the FWM wavelength conversion of 40 Gb/s (20 GBd) NRZ-DQPSK data. A bulk SOA with 21 dB gain and 10 dBm output saturation power is used. The Q-factors of the input and wavelength converted signal are measured. Some signal regeneration properties are shown. A Q-factor improvement up to 1.7 dB is observed.