Amplitude Regenerative Characteristics of RZDPSK Wavelength Converter Based on FourWave M.pdf

CHIN.PHYS.LETT. Vol. 25, No. 5 (2008) 1697 Amplitude Regenerative Characteristics of RZ-DPSK Wavelength Converter Based on Four-Wave Mixing in SOA JIANG Huan()∗∗ , WEN He(), HAN Liu-Yan(), GUO Yi-Li(), ZHANG Han-Yi() Department of Electronic Engineering, Tsinghua University, Beijing 100084 (Received 19 December 2007) We investigate the phase-preserving amplitude regenerative characteristics of the return-to-zero (RZ) differential- phase-shift-keying (DPSK) wavelength conversion based on four-wave mixing (FWM) in a semiconductor optical amplifier (SOA). The Q-factor and the optical signal-to-noise ratio (OSNR) before and after conversion are experimentally obtained and analysed in different input noise power levels. In both the continuous-wave and synchronous clock pumping cases, we find that there is amplitude clamping in the FWM conversion due to the gain saturation of SOA, which can suppress the amplitude fluctuation of the converted DPSK signal before and after demodulation. We have achieved 2-dB Q penalty improvement in our experiment demonstration of 10Gbit/s RZ-DPSK signal with OSNR lower than 19 dB. PACS: 42. 79. Nv, 42. 65. Ky, 85. 60. −q The semiconductor optical amplifier (SOA) is tively, before and after 80-km transmission through a good candidate for all-optical processing due to single-mode fibre relative to the latter. In this study, its low power consumption, low cost, small foot- we demonstrate the phase-preserving amplitude re- print, and easy integration features.[1,2] The SOA- generative characteristics of the RZ-DPSK wavelength based application has received considerable interes