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 m/xing （FWM） in a semiconduc...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 m/xing （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 lOGbit/s RZ-DPSK signal with OSNR lower than 19dB.展开更多
Using differential detection, we perform polarization-multiplexing 160-Gb/s optical non-return-to-zero （NRZ） differential quadrature phase shift keying （DQPSK） signal transmission over 100-kin standard single mode...Using differential detection, we perform polarization-multiplexing 160-Gb/s optical non-return-to-zero （NRZ） differential quadrature phase shift keying （DQPSK） signal transmission over 100-kin standard single mode fiber at a bit error rate （BER） of less than 10^-9. The enabling technology includes clock recovery, fine dispersion compensation, and polarization tracking for de-multiplexing. Furthermore, a hybrid clock recovery scheme is proposed. The scheme is realized with ordinary devices using an optoelectrical modulator to down-convert the clock frequency and a phase-locked loop for filtering, which can provide an indication signal that simultaneously monitors residual dispersion and tracking polarization.展开更多
The relation between the phase shift and the mean optical power （MOP） output from a delay-line inter- ferometer （DLI） port applied for phase-shift keying （PSK） signal demodulation is proven of a cosine law irrel...The relation between the phase shift and the mean optical power （MOP） output from a delay-line inter- ferometer （DLI） port applied for phase-shift keying （PSK） signal demodulation is proven of a cosine law irrelevant to signal modulation condition. The variation amplitude of the MOP is proportional to the transition duration of the modulation pulses. This phenomenon is interpreted as the result of the sta- tistical and waveform characteristics of the PSK. The conclusions verified by simulation and experiment are generalized to other modulation formats and then applied to phase detuning monitoring, delay time judgment of DLI, and independence of modulation data assessment.展开更多
基金Supported by the National Natural Science Foundation of China under Grant No 60520130298.
文摘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 m/xing （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 lOGbit/s RZ-DPSK signal with OSNR lower than 19dB.
基金supported in part by the National Natural Science Foundation of China(Nos. 60736003,61025004,and 61032005)the National "863" Program of China(Nos.2009AA01Z223 and 2009AA01Z253)
文摘Using differential detection, we perform polarization-multiplexing 160-Gb/s optical non-return-to-zero （NRZ） differential quadrature phase shift keying （DQPSK） signal transmission over 100-kin standard single mode fiber at a bit error rate （BER） of less than 10^-9. The enabling technology includes clock recovery, fine dispersion compensation, and polarization tracking for de-multiplexing. Furthermore, a hybrid clock recovery scheme is proposed. The scheme is realized with ordinary devices using an optoelectrical modulator to down-convert the clock frequency and a phase-locked loop for filtering, which can provide an indication signal that simultaneously monitors residual dispersion and tracking polarization.
基金supported in part by the National Natural Science Foundation of China(Nos. 61007045,61025004 and 61032005)the National "863" Program of China(Nos.2009AA01Z223 and 2009AA01Z253)
文摘The relation between the phase shift and the mean optical power （MOP） output from a delay-line inter- ferometer （DLI） port applied for phase-shift keying （PSK） signal demodulation is proven of a cosine law irrelevant to signal modulation condition. The variation amplitude of the MOP is proportional to the transition duration of the modulation pulses. This phenomenon is interpreted as the result of the sta- tistical and waveform characteristics of the PSK. The conclusions verified by simulation and experiment are generalized to other modulation formats and then applied to phase detuning monitoring, delay time judgment of DLI, and independence of modulation data assessment.
