Using numerical simulations, the nonlinear transmission performance of polarization-division-multiplexed quadrature-phase-shift-keying （PDM-QPSK） coherent systems is studied. It is found that inter-channel cross-pol...Using numerical simulations, the nonlinear transmission performance of polarization-division-multiplexed quadrature-phase-shift-keying （PDM-QPSK） coherent systems is studied. It is found that inter-channel cross-polarization modulation （XPolM） induced nonlinear polarization scattering can significantly degrade the transmission performance of PDM-QPSK coherent systems and change the perspective of dispersion management in optical coherent transmission systems. Some techniques to mitigate nonlinear polarization scattering in dispersion-managed PDM coherent transmission systems are discussed, including the use of time-interleaved return-to-zero （RZ） PDM formats, the use of periodic-group-delay PGD dispersion compensators, and the judicious addition of some polarization-mode-dispersion （PMD） in the transmission link. It is shown that if nonlinear polarization scattering can be well mitigated, a polarization multiplexed optical coherent transmission system with dispersion management could perform better than that without it.展开更多
Optical transfer delay(OTD)is essential for distributed coherent systems,optically controlled phased arrays,fiber sensing systems,and quantum communication systems.However,existing OTD measurement techniques typically...Optical transfer delay(OTD)is essential for distributed coherent systems,optically controlled phased arrays,fiber sensing systems,and quantum communication systems.However,existing OTD measurement techniques typically involve trade-offs among accuracy,range,and speed,limiting the application in the fields.Herein,we propose a single-shot OTD measurement approach that simultaneously achieves high-accuracy,long-range,and high-speed measurement.A microwave photonic phase-derived ranging with a nonlinear interval microwave frequency comb(MFC)and a discrete frequency sampling technique is proposed to conserve both frequency and time resources,ensuring high-accuracy and ambiguity-free measurements.In the proof-of-concept experiment,a delay measurement uncertainty at the 10^(-9) level with a single 10μs sampling time is first reported,to our knowledge.The method is also applied to coherently combine two distributed signals at 31.8 GHz,separated by a 2 km optical fiber.A minimal gain loss of less than 0.0038 d B compared to the theoretical value was achieved,corresponding to an OTD synchronization accuracy of 0.3 ps.展开更多
文摘Using numerical simulations, the nonlinear transmission performance of polarization-division-multiplexed quadrature-phase-shift-keying （PDM-QPSK） coherent systems is studied. It is found that inter-channel cross-polarization modulation （XPolM） induced nonlinear polarization scattering can significantly degrade the transmission performance of PDM-QPSK coherent systems and change the perspective of dispersion management in optical coherent transmission systems. Some techniques to mitigate nonlinear polarization scattering in dispersion-managed PDM coherent transmission systems are discussed, including the use of time-interleaved return-to-zero （RZ） PDM formats, the use of periodic-group-delay PGD dispersion compensators, and the judicious addition of some polarization-mode-dispersion （PMD） in the transmission link. It is shown that if nonlinear polarization scattering can be well mitigated, a polarization multiplexed optical coherent transmission system with dispersion management could perform better than that without it.
基金National Natural Science Foundation of China(62271249,62075095)Fundamental Research Funds for the Central UniversitiesFunding for Outstanding Doctoral Dissertation in NUAA(BCXJ24-09)。
文摘Optical transfer delay(OTD)is essential for distributed coherent systems,optically controlled phased arrays,fiber sensing systems,and quantum communication systems.However,existing OTD measurement techniques typically involve trade-offs among accuracy,range,and speed,limiting the application in the fields.Herein,we propose a single-shot OTD measurement approach that simultaneously achieves high-accuracy,long-range,and high-speed measurement.A microwave photonic phase-derived ranging with a nonlinear interval microwave frequency comb(MFC)and a discrete frequency sampling technique is proposed to conserve both frequency and time resources,ensuring high-accuracy and ambiguity-free measurements.In the proof-of-concept experiment,a delay measurement uncertainty at the 10^(-9) level with a single 10μs sampling time is first reported,to our knowledge.The method is also applied to coherently combine two distributed signals at 31.8 GHz,separated by a 2 km optical fiber.A minimal gain loss of less than 0.0038 d B compared to the theoretical value was achieved,corresponding to an OTD synchronization accuracy of 0.3 ps.
