采用多量子阱掩埋条形（BRS）增益芯片和拉锥光纤布拉格光栅（FBG）,制作了1.5μm波段FBG外腔式窄线宽半导体激光器。封装后器件实现了全电流范围内稳定单模窄线宽激光输出。30~250 m A驱动电流下线宽小于15.48 k Hz,实测最小线宽为6.42...采用多量子阱掩埋条形（BRS）增益芯片和拉锥光纤布拉格光栅（FBG）,制作了1.5μm波段FBG外腔式窄线宽半导体激光器。封装后器件实现了全电流范围内稳定单模窄线宽激光输出。30~250 m A驱动电流下线宽小于15.48 k Hz,实测最小线宽为6.42 k Hz,频率稳定度为7.2×10-8/s,边模抑制比大于40 d B,最大出纤功率大于10 m W。这种集成窄线宽激光器性能优异,且制作成本低,工艺简单,适于批量生产,可应用于400 Gb/s相干通信系统的发射源与接收机本振源。展开更多
The dissipative Kerr soliton microcomb provides a promising laser source for wavelength-division multiplexing(WDM)communication systems thanks to its compatibility with chip integration.However,the soliton microcomb c...The dissipative Kerr soliton microcomb provides a promising laser source for wavelength-division multiplexing(WDM)communication systems thanks to its compatibility with chip integration.However,the soliton microcomb commonly suffers from a low-power level due to the intrinsically limited energy conversion efficiency from the continuous-wave pump laser to ultra-short solitary pulses.Here,we exploit laser injection locking to amplify and equalize dissipative Kerr soliton comb lines,superior gain factor larger than 30 dB,and optical-signal-to-noise-ratio(OSNR)as high as 60 dB obtained experimentally,providing a potential pathway to constitute a high-power chip-integrated WDM laser source for optical communications.展开更多
Spatial modedivision multiplexing is emerging as a potential solution to further increasing optical fiber capacity and spectral efficiency. We report a dualmode, dualpolarization transmission method based on modeselec...Spatial modedivision multiplexing is emerging as a potential solution to further increasing optical fiber capacity and spectral efficiency. We report a dualmode, dualpolarization transmission method based on modeselective excitation and detection over a twomode fiber. In particular, we present 107 Gbit/s coherent optical OFDM （COOFDM） transmission over a 4.5 km twomode fiber using LP and LP. modes in which mode separation is performed optically.展开更多
The UWA channel is characterized as a time-dispersive rapidly fading channel, which in addition exhibits Doppler instabilities and limited bandwidth. To eliminate inter- symbol interference caused by multipath propaga...The UWA channel is characterized as a time-dispersive rapidly fading channel, which in addition exhibits Doppler instabilities and limited bandwidth. To eliminate inter- symbol interference caused by multipath propagation, spatial diversity equalization is the main technical means. The paper combines the passive phase conjugation and spatial processing to maximize the output array gain. It uses signal-to-noise-plus-interference to evaluate the quality of signals received at different channels. The amplitude of signal is weighted using Sigmoid function. Second order PLL can trace the phase variation caused by channel, so the signal can be accumulated in the same phase. The signals received at different channels need to be normal- ized. It adopts fractional-decision feedback diversity equalizer （FDFDE） and achieves diversity equalization by using different channel weighted coefficients. The simulation and lake trial data processing results show that, the optimized diversity receiving equalization algorithm can im- prove communication system＇s ability in tracking the change of underwater acoustic channel, offset the impact of multipath and noise and improve the performance of communication system. The performance of the communication receiving system is better than that of the equal gain combination. At the same time, the bit error rate （BER） reduces 1.8%.展开更多
A new method coherent DWDM system has been proposed. Standard method uses 90 wavelengths with channel capacity 100 G, so total capacity amounts to 9 Terabit, optical power is P. New “channel super” (CS) consists of ...A new method coherent DWDM system has been proposed. Standard method uses 90 wavelengths with channel capacity 100 G, so total capacity amounts to 9 Terabit, optical power is P. New “channel super” (CS) consists of 15 wavelengths, number of CS is 6, so total number of wavelengths is 90 too, total capacity is 6 Terabit, but optical power is 4/15P. Over ULH and EULH markets, standard approach will be forced to reduce the total capacity to 2.4 Terabit with optical power 4/15P as in proposed method. But the new can reach 6 Terabit with the same optical power 4/15P.展开更多
We propose and experimentally demonstrate a universal and blind polarization-state tracking scheme for M-quadrature amplitude modulation（QAM） signals based on a decision-free radius-directed linear Kalman filter（RD...We propose and experimentally demonstrate a universal and blind polarization-state tracking scheme for M-quadrature amplitude modulation（QAM） signals based on a decision-free radius-directed linear Kalman filter（RD-LKF）.The polarization tracking performance is investigated through simulation and experiments for both quadrature phase-shift keying（QPSK） and 16-QAM signals.The influence of the filter parameters on the static polarization demultiplexing performance and dynamic tracking capability are discussed via simulation.The optimization strategy of the filter parameters in modulation-format-independent scenarios is proposed and simulations are carried out to evaluate the polarization demultiplexing penalty for QPSK,16 QAM,and hybrid QPSK/16 QAM signals.Finally,the proposed decision-free RD-LKF is experimentally compared to the respective algorithms of constant modulus algorithm and multimodulus algorithm for QPSK and 16-QAM and the advantage of ultrafast polarization tracking ability is confirmed.展开更多
文摘采用多量子阱掩埋条形（BRS）增益芯片和拉锥光纤布拉格光栅（FBG）,制作了1.5μm波段FBG外腔式窄线宽半导体激光器。封装后器件实现了全电流范围内稳定单模窄线宽激光输出。30~250 m A驱动电流下线宽小于15.48 k Hz,实测最小线宽为6.42 k Hz,频率稳定度为7.2×10-8/s,边模抑制比大于40 d B,最大出纤功率大于10 m W。这种集成窄线宽激光器性能优异,且制作成本低,工艺简单,适于批量生产,可应用于400 Gb/s相干通信系统的发射源与接收机本振源。
基金supported by the National Key R&D Program of China(Nos.2019YFB-2203103 and 2018YFA0307400)the National Natural Science Foundation of China(NSFC)(Nos.62001086 and 61705033)。
文摘The dissipative Kerr soliton microcomb provides a promising laser source for wavelength-division multiplexing(WDM)communication systems thanks to its compatibility with chip integration.However,the soliton microcomb commonly suffers from a low-power level due to the intrinsically limited energy conversion efficiency from the continuous-wave pump laser to ultra-short solitary pulses.Here,we exploit laser injection locking to amplify and equalize dissipative Kerr soliton comb lines,superior gain factor larger than 30 dB,and optical-signal-to-noise-ratio(OSNR)as high as 60 dB obtained experimentally,providing a potential pathway to constitute a high-power chip-integrated WDM laser source for optical communications.
文摘Spatial modedivision multiplexing is emerging as a potential solution to further increasing optical fiber capacity and spectral efficiency. We report a dualmode, dualpolarization transmission method based on modeselective excitation and detection over a twomode fiber. In particular, we present 107 Gbit/s coherent optical OFDM （COOFDM） transmission over a 4.5 km twomode fiber using LP and LP. modes in which mode separation is performed optically.
基金supported by National Natural Science Foundation of China(61531018)
文摘The UWA channel is characterized as a time-dispersive rapidly fading channel, which in addition exhibits Doppler instabilities and limited bandwidth. To eliminate inter- symbol interference caused by multipath propagation, spatial diversity equalization is the main technical means. The paper combines the passive phase conjugation and spatial processing to maximize the output array gain. It uses signal-to-noise-plus-interference to evaluate the quality of signals received at different channels. The amplitude of signal is weighted using Sigmoid function. Second order PLL can trace the phase variation caused by channel, so the signal can be accumulated in the same phase. The signals received at different channels need to be normal- ized. It adopts fractional-decision feedback diversity equalizer （FDFDE） and achieves diversity equalization by using different channel weighted coefficients. The simulation and lake trial data processing results show that, the optimized diversity receiving equalization algorithm can im- prove communication system＇s ability in tracking the change of underwater acoustic channel, offset the impact of multipath and noise and improve the performance of communication system. The performance of the communication receiving system is better than that of the equal gain combination. At the same time, the bit error rate （BER） reduces 1.8%.
文摘A new method coherent DWDM system has been proposed. Standard method uses 90 wavelengths with channel capacity 100 G, so total capacity amounts to 9 Terabit, optical power is P. New “channel super” (CS) consists of 15 wavelengths, number of CS is 6, so total number of wavelengths is 90 too, total capacity is 6 Terabit, but optical power is 4/15P. Over ULH and EULH markets, standard approach will be forced to reduce the total capacity to 2.4 Terabit with optical power 4/15P as in proposed method. But the new can reach 6 Terabit with the same optical power 4/15P.
基金supported by the National Natural Science Foundation of China(Nos.61205046,61401020,and 61575051)the Shenzhen Municipal Science and Technology Plan Project(Nos.JCYJ20150327155705357,KQCX2015032409501296,and JSGG20150529153336124,and JCYJ20150529114045265)the Hong Kong Government General Research Fund(GRF)(No.PolyU152079/14E)
文摘We propose and experimentally demonstrate a universal and blind polarization-state tracking scheme for M-quadrature amplitude modulation（QAM） signals based on a decision-free radius-directed linear Kalman filter（RD-LKF）.The polarization tracking performance is investigated through simulation and experiments for both quadrature phase-shift keying（QPSK） and 16-QAM signals.The influence of the filter parameters on the static polarization demultiplexing performance and dynamic tracking capability are discussed via simulation.The optimization strategy of the filter parameters in modulation-format-independent scenarios is proposed and simulations are carried out to evaluate the polarization demultiplexing penalty for QPSK,16 QAM,and hybrid QPSK/16 QAM signals.Finally,the proposed decision-free RD-LKF is experimentally compared to the respective algorithms of constant modulus algorithm and multimodulus algorithm for QPSK and 16-QAM and the advantage of ultrafast polarization tracking ability is confirmed.
