The Experts below are selected from a list of 105 Experts worldwide ranked by ideXlab platform
Deming Liu - One of the best experts on this subject based on the ideXlab platform.
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Impact of Sampling Source Repetition Frequency in Linear Optical Sampling
IEEE Photonics Technology Letters, 2016Co-Authors: Jue Song, Bin Liu, Ming Tang, Perry Ping Shum, Deming LiuAbstract:We report the repetition frequency constraint of a passively mode-locked fiber laser (PMFL) for linear optical Sampling based M-ary phase-shift keying (PSK) constellation characterization, based on the commonly used Viterbi–Viterbi carrier phase estimation algorithm. Referred to the error vector magnitude (EVM) value by the conventional high-speed electronic coherent detection, we put forward a benchmark of EVM $_{\rm {RMS\_{}error}}$ to evaluate the accuracy of constellation characterization by linear optical Sampling. Due to the repetition frequency constraint of the PMFL, the EVM $_{\rm {RMS\_{}error}}$ will reach an ultimate value of 0.25% for the purpose of PSK constellation characterization, while it is insensitive to the signal symbol rate. The analytical results of a typical 28-GBaud QPSK signal well agree with those of the simulation and the experiment, therefore providing guidance for the repetition frequency optimization of PMFL-based linear optical Sampling.
Olivier Sentieys - One of the best experts on this subject based on the ideXlab platform.
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Impact of Sampling-Source Extinction Ratio in Linear Optical Sampling
IEEE Photonics Technology Letters, 2013Co-Authors: Trung Hien Nguyen, Fausto Gomez Agis, Laurent Bramerie, Mathilde Gay, Jean-claude Simon, Olivier SentieysAbstract:We report on the impact of the Sampling-Source extinction ratio (ER) in a linear optical Sampling system. To this effect, an analytical model is developed and contrasted with experimental data and numerical simulation, to determine the operational limits of the monitoring system. The ER of the reconstructed signal consists of a combined contribution from the magnitude of the symbol under test and the magnitude of the product between its neighboring symbols and the corresponding subpulses of the Sampling Source. The sampled signal can be completely reconstructed from its samples for ERs of the Sampling Source above 35 dB.
Trung Hien Nguyen - One of the best experts on this subject based on the ideXlab platform.
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Theoretical and experimental study of optical solutions for analog-to-digital conversion of high bit-rate signals
2015Co-Authors: Trung Hien NguyenAbstract:Bi-dimensional modulation formats based on amplitude and phase signal modulation, are now commonly used in optical communications thanks to breakthroughs in the field of electronic and digital signal processing (DSP) required in coherent optical receivers. Photonic solutions could compensate for nowadays limitations of electrical circuits bandwidth by facilitating the signal processing parallelization. Photonic is particularly interesting for signal Sampling thanks to available stable optical clocks. The heart of the present work concerns analog-to-digital conversion (ADC) as a key element in coherent detection. A prototype of linear optical Sampling using an original solution for the optical Sampling Source, is built and validated with the successful equivalent time reconstruction of NRZ, QPSK and 16-QAM signals. Some optical and electrical limitations of the system are experimentally and numerically analyzed, notably the extinction ratio of the optical Source or the ADC parameters (bandwidth, integration time, effective number of bits ENOB). Moreover, some new DSPs tools are developed for optical transmission using bi-dimensional modulation formats (amplitude and phase). Two solutions are proposed for IQ quadrature imbalance compensation in single carrier optical coherent transmission: an original method of maximum signal-to-noise ratio estimation (MSEM) and a new structure for joint compensation and equalization; these methods are experimentally and numerically validated with 16-QAM signals. Moreover, an improved solution for carrier recovery (frequency offset and phase estimation) based on a circular harmonic expansion of a maximum loglikelihood function is studied for the first time in the context of optical telecommunications. This solution which can operate with any kind of bi-dimensional modulation format signal is numerically validated up to 128-QAM. All the DSP tools developed in this work are finally used in a demonstration of a 10 Gbaud QPSK 100 km transmission experiment, featuring a strong non-linear phase noise limitation and regenerated using a phase preserving and power limiting function based on a photonic crystal nanocavity.
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Impact of Sampling-Source Extinction Ratio in Linear Optical Sampling
IEEE Photonics Technology Letters, 2013Co-Authors: Trung Hien Nguyen, Fausto Gomez Agis, Laurent Bramerie, Mathilde Gay, Jean-claude Simon, Olivier SentieysAbstract:We report on the impact of the Sampling-Source extinction ratio (ER) in a linear optical Sampling system. To this effect, an analytical model is developed and contrasted with experimental data and numerical simulation, to determine the operational limits of the monitoring system. The ER of the reconstructed signal consists of a combined contribution from the magnitude of the symbol under test and the magnitude of the product between its neighboring symbols and the corresponding subpulses of the Sampling Source. The sampled signal can be completely reconstructed from its samples for ERs of the Sampling Source above 35 dB.
Jue Song - One of the best experts on this subject based on the ideXlab platform.
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Impact of Sampling Source Repetition Frequency in Linear Optical Sampling
IEEE Photonics Technology Letters, 2016Co-Authors: Jue Song, Bin Liu, Ming Tang, Perry Ping Shum, Deming LiuAbstract:We report the repetition frequency constraint of a passively mode-locked fiber laser (PMFL) for linear optical Sampling based M-ary phase-shift keying (PSK) constellation characterization, based on the commonly used Viterbi–Viterbi carrier phase estimation algorithm. Referred to the error vector magnitude (EVM) value by the conventional high-speed electronic coherent detection, we put forward a benchmark of EVM $_{\rm {RMS\_{}error}}$ to evaluate the accuracy of constellation characterization by linear optical Sampling. Due to the repetition frequency constraint of the PMFL, the EVM $_{\rm {RMS\_{}error}}$ will reach an ultimate value of 0.25% for the purpose of PSK constellation characterization, while it is insensitive to the signal symbol rate. The analytical results of a typical 28-GBaud QPSK signal well agree with those of the simulation and the experiment, therefore providing guidance for the repetition frequency optimization of PMFL-based linear optical Sampling.
Cheolhwan Kim - One of the best experts on this subject based on the ideXlab platform.
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Requirements for the Sampling Source in coherent linear Sampling
Optics express, 2004Co-Authors: Inwoong Kim, Cheolhwan KimAbstract:Complex envelope measurement using coherent linear optical Sampling with mode-locked Sources is investigated. It is shown that reliable measurement of the phase requires that one of the optical modes of the mode-locked laser be locked to the optical carrier of the data signal to be measured. Carrier-envelope offset (CEO) is found to have negligible effect on the measurement. Measurement errors of the intensity profile and phase depend on the pulsewidth and chirp of the Sampling pulses as well as the detuning between the carrier frequencies of the data signal and the center frequency of Sampling Source.
