Nyquist

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Toshihiko Hirooka - One of the best experts on this subject based on the ideXlab platform.

Pengyu Guan - One of the best experts on this subject based on the ideXlab platform.

  • time lens based optical fourier transformation for all optical signal processing of spectrally efficient data
    Journal of Lightwave Technology, 2017
    Co-Authors: Pengyu Guan, Michael Galili, Kasper Meldgaard Roge, Mads Lillieholm, Toshio Morioka, Leif Katsuo Oxenlowe
    Abstract:

    We review recent progress in the use of time lens-based optical Fourier transformation for advanced all-optical signal processing. A novel time lens-based complete optical Fourier transformation (OFT) technique is introduced. This complete OFT is based on two quadratic phase-modulation stages using four-wave mixing, separated by a dispersive medium, which enables time-to-frequency and frequency-to-time conversions simultaneously, thus performing an exchange between the temporal and spectral profiles of the input signal. Using the proposed complete OFT, several advanced all-optical signal processing schemes for spectrally-efficient systems and networks have been achieved, including all-optical generation, detection and format conversion of spectrally-efficient signals. The spectrally-efficient signals in this paper mainly refer to efficiently multiplexed signals with a high symbol rate per Hz, such as orthogonal frequency division multiplexing, Nyquist wavelength-division multiplexing (Nyquist-WDM), and Nyquist optical time division multiplexing (Nyquist-OTDM) signals.

  • all optical ultra high speed ofdm to Nyquist wdm conversion based on complete optical fourier transformation
    Journal of Lightwave Technology, 2016
    Co-Authors: Pengyu Guan, Michael Galili, Kasper Meldgaard Roge, Hans Christian Hansen Mulvad, Mads Lillieholm, Toshio Morioka, Leif Katsuo Oxenlowe
    Abstract:

    We propose a novel all-optical ultra-high-speed orthogonal frequency-division multiplexing (OFDM) to Nyquist wavelength-division multiplexing (Nyquist-WDM) conversion scheme, achieved by exchanging the temporal and spectral profiles using a complete optical Fourier transformation (OFT). This scheme enables high-speed OFDM to Nyquist-WDM conversion without complex optical/electrical/optical conversion. The all-optical OFDM transmitter is based on the generation of OFDM symbols with a low duty cycle by rectangular temporal gating, which in combination with optical time-division multiplexing yields a higher symbol-rate OFDM signal. In the receiver, the converted Nyquist-WDM super-channel is WDM demultiplexed into individual Nyquist-WDM channels using a rectangular optical bandpass filter, followed by optical sampling at the intersymbol-interference free point. In the experimental demonstration, a single-polarization 8-subcarrier 640 Gb/s differential phase-shift keying OFDM super-channel with a spectral efficiency (SE) of 0.8 symbol/s/Hz is generated. The OFDM super-channel is then converted to eight 80-Gb/s Nyquist-WDM channels by complete OFT. The complete OFT is based on two quadratic phase-modulation stages using four-wave mixing, separated by a dispersive medium. In the receiver, a BER < 10−9 is obtained for all channels. The SE remains unchanged after conversion.

  • Combined Optical and Electrical Spectrum Shaping for High-Baud-Rate Nyquist-WDM Transceivers
    IEEE Photonics Journal, 2016
    Co-Authors: Edson P. Da Silva, Fabian Schwartau, Simone Gaiarin, Miguel I. Olmedo, Armand Vedadi, Stefan Preußler, Robert Borkowski, Molly Piels, Michael Galili, Pengyu Guan
    Abstract:

    We discuss the benefits and limitations of optical time-division multiplexing (OTDM) techniques based on the optical generation of a periodic train of sinc pulses for wavelength-division multiplexing (WDM) transmission at high baud rates. It is shown how the modulated OTDM spectrum bandwidth is related to the optical comb parameters and the pulse shaping of the modulating waveforms in the electrical domain. Such dependence may result in broadening of the modulated spectra, which can degrade the performance of Nyquist-WDM systems due to interchannel crosstalk penalties. However, it is shown and experimentally demonstrated that the same technique of optical pulse train generation can be allied with digital pulse shaping to improve the confinement of the modulated spectrum toward the Nyquist limit independently of the number of OTDM tributaries used. To investigate the benefits of the proposed approach, we demonstrate the first WDM Nyquist-OTDM signal generation based on the periodic train of sinc pulses and electrical spectrum shaping. Straight line transmission of five 112.5-Gbd Nyquist-OTDM dual-polarization quadrature phase-shift keying (QPSK) channels is demonstrated over a dispersion uncompensated link up to 640 km, with full-field coherent detection at the receiver. It is shown that such a design strategy effectively improves the spectral confinement of the modulated OTDM signal, providing a minimum intercarrier crosstalk penalty of 1.5 dB in baud-rate-spaced Nyquist-WDM systems.

  • Combined Optical and Electrical Spectrum Shaping for High-Baud-Rate Nyquist-WDM
    2016
    Co-Authors: Edson P. Da Silva, Fabian Schwartau, Simone Gaiarin, Miguel I. Olmedo, Armand Vedadi, Pengyu Guan, Robert Borkowski, Molly Piels, Michael Galili, Sergei Popov
    Abstract:

    Abstract: We discuss the benefits and limitations of optical time-division multiplexing(OTDM) techniques based on the optical generation of a periodic train of sinc pulses forwavelength-division multiplexing (WDM) transmission at high baud rates. It is shownhow the modulated OTDM spectrum bandwidth is related to the optical comb parametersand the pulse shaping of the modulating waveforms in the electrical domain. Such de-pendence may result in broadening of the modulated spectra, which can degrade theperformance of Nyquist-WDM systems due to interchannel crosstalk penalties. However,it is shown and experimentally demonstrated that the same technique of optical pulsetrain generation can be allied with digital pulse shaping to improve the confinement ofthe modulated spectrum toward the Nyquist limit independently of the number of OTDMtributaries used. To investigate the benefits of the proposed approach, we demonstratethe first WDM Nyquist-OTDM signal generation based on the periodic train of sinc pulsesand electrical spectrum shaping. Straight line transmission of five 112.5-Gbd Nyquist-OTDM dual-polarization quadrature phase-shift keying (QPSK) channels is demon-strated over a dispersion uncompensated link up to 640 km, with full-field coherentdetection at the receiver. It is shown that such a design strategy effectively improves thespectral confinement of the modulated OTDM signal, providing a minimum intercarriercrosstalk penalty of 1.5 dB in baud-rate-spaced Nyquist-WDM systems.Index Terms: Coherent communications, Nyquist-OTDM.

  • highly dispersion tolerant 160 gbaud optical Nyquist pulse tdm transmission over 525 km
    Optics Express, 2012
    Co-Authors: Toshihiko Hirooka, Pengyu Guan, Peng Ruan, Masataka Nakazawa
    Abstract:

    We demonstrate an optical Nyquist pulse TDM (Nyquist OTDM) transmission at 160 Gbaud with a substantial increase in the dispersion tolerance compared with a conventional OTDM transmission. Optical Nyquist pulses can be bit-interleaved to ultrahigh symbol rate without suffering from intersymbol interference due to its zero-crossing property at every symbol interval. This allows the signal bandwidth to be greatly narrowed compared to typical pulse waveforms such as Gaussian or sech profile. By virtue of this property, a dispersion tolerance over ± 8 ps/nm was successfully realized in 160 Gbaud, 525 km transmission.

Masataka Nakazawa - One of the best experts on this subject based on the ideXlab platform.

  • subpicosecond coherent Nyquist pulse generation for 1 tbaud transmission using a c 2 h 2 frequency stabilized cw laser and a 40 ghz optical comb generator
    Conference on Lasers and Electro-Optics, 2017
    Co-Authors: Daiki Suzuki, Toshihiko Hirooka, Keisuke Kasai, Masataka Nakazawa
    Abstract:

    A 40-GHz coherent Nyquist pulse was generated from a C 2 H 2 frequency-stabilized CW fiber laser and an optical comb generator. A 1.5-THz flat-top comb was shaped into 680-fs Nyquist pulses, which are applicable to 1.28-Tbaud transmission.

  • single channel 1 92 tbit s 64 qam coherent Nyquist orthogonal tdm transmission with a spectral efficiency of 10 6 bit s hz
    Journal of Lightwave Technology, 2016
    Co-Authors: David Odeke Otuya, Toshihiko Hirooka, Keisuke Kasai, Masataka Nakazawa
    Abstract:

    We have proposed a coherent optical Nyquist pulse and its high-speed optical time division multiplexing (OTDM), in which data signals can be transmitted at a bandwidth as low as the baud rate. By taking advantage of the time-domain orthogonality of coherent Nyquist pulses, Nyquist OTDM signals can be demultiplexed with a high SNR, despite a large intersymbol overlap by adopting Nyquist-LO pulses. With this technique, we successfully transmitted a 1.92 Tbit/s, polarization-division-multiplexed 64 quadrature amplitude modulation Nyquist pulse signal over 225 km within a signal bandwidth of 170 GHz, leading to a potential spectral efficiency of as high as 10.6 bit/s/Hz.

  • 640 gbaud 1 28 tbit s ch optical Nyquist pulse transmission over 525 km with substantial pmd tolerance
    Optics Express, 2013
    Co-Authors: Koudai Harako, Daiki Seya, Toshihiko Hirooka, Masataka Nakazawa
    Abstract:

    We report a substantial increase in PMD tolerance in a single-channel ultrahigh-speed transmission using optical Nyquist pulses. We demonstrate both analytically and experimentally a large reduction in depolarization-induced crosstalk with optical Nyquist pulses, which is one of the major obstacles facing polarization-multiplexed ultrashort pulse transmission. By taking advantage of the high PMD tolerance, a low-penalty 1.28 Tbit/s/ch optical Nyquist TDM transmission at 640 Gbaud was achieved over 525 km.

  • linear and nonlinear propagation of optical Nyquist pulses in fibers
    Optics Express, 2012
    Co-Authors: Toshihiko Hirooka, Masataka Nakazawa
    Abstract:

    We present an analytical and numerical description of optical Nyquist pulse propagation in optical fibers in the presence of dispersion and nonlinearity. An optical Nyquist pulse has a profile given by the sinc-like impulse response of a Nyquist filter, which has periodic zero-crossing points at every symbol interval. This property makes it possible to interleave bits to an ultrahigh symbol rate with no intersymbol interference in spite of the strong overlap between adjacent pulses. We analyze how this periodic zero-crossing property is maintained or affected by the fiber dispersion and nonlinearity, and show that it is better maintained against nonlinearity in the presence of normal dispersion.

  • highly dispersion tolerant 160 gbaud optical Nyquist pulse tdm transmission over 525 km
    Optics Express, 2012
    Co-Authors: Toshihiko Hirooka, Pengyu Guan, Peng Ruan, Masataka Nakazawa
    Abstract:

    We demonstrate an optical Nyquist pulse TDM (Nyquist OTDM) transmission at 160 Gbaud with a substantial increase in the dispersion tolerance compared with a conventional OTDM transmission. Optical Nyquist pulses can be bit-interleaved to ultrahigh symbol rate without suffering from intersymbol interference due to its zero-crossing property at every symbol interval. This allows the signal bandwidth to be greatly narrowed compared to typical pulse waveforms such as Gaussian or sech profile. By virtue of this property, a dispersion tolerance over ± 8 ps/nm was successfully realized in 160 Gbaud, 525 km transmission.

David Hillerkuss - One of the best experts on this subject based on the ideXlab platform.

  • single laser 32 5 tbit s Nyquist wdm transmission
    IEEE\ OSA Journal of Optical Communications and Networking, 2012
    Co-Authors: David Hillerkuss, Rene Schmogrow, Matthias Meyer, S Wolf, M Jordan, P Kleinow, N Lindenmann, P C Schindler, Argishti Melikyan, Xin Yang
    Abstract:

    We demonstrate single-laser 32.5 Tbit/s 16QAM Nyquist wavelength division multiplexing transmission over a total length of 227 km of SMF-28 without optical dispersion compensation. A number of 325 optical carriers is derived from a single laser and encoded with dual-polarization 16QAM data using sinc-shaped Nyquist pulses. As we use no guard bands, the carriers have a spacing of 12.5 GHz equal to the symbol rate or Nyquist bandwidth of the data. We achieve a net spectral efficiency of 6.4 bit/s/Hz using a software-defined transmitter, which generates the electric drive signals for the electro-optic modulator in real time.

  • Nyquist frequency division multiplexing for optical communications
    Conference on Lasers and Electro-Optics 2012, 2012
    Co-Authors: Rene Schmogrow, Stefan Wolf, Benedikt Baeuerle, David Hillerkuss, B. Nebendahl, Christian Koos, Wolfgang Freude, Juerg Leuthold
    Abstract:

    We demonstrate a novel Nyquist FDM scheme where electrical Nyquist pulses on different subcarrier frequencies are transmitted optically. High spectral efficiency, asynchronous operation, and dynamic bandwidth allocation are supported.

  • single laser 32 5 tbit s Nyquist wdm transmission
    arXiv: Networking and Internet Architecture, 2012
    Co-Authors: David Hillerkuss, Rene Schmogrow, Matthias Meyer, S Wolf, M Jordan, P Kleinow, N Lindenmann, P C Schindler, Argishti Melikyan, Xin Yang
    Abstract:

    We demonstrate 32.5 Tbit/s 16QAM Nyquist WDM transmission over a total length of 227 km of SMF-28 without optical dispersion compensation. A number of 325 optical carriers are derived from a single laser and encoded with dual-polarization 16QAM data using sinc-shaped Nyquist pulses. As we use no guard bands, the carriers have a spacing of 12.5 GHz equal to the Nyquist bandwidth of the data. We achieve a high net spectral efficiency of 6.4 bit/s/Hz using a software-defined transmitter which generates the electrical modulator drive signals in real-time.

  • real time Nyquist pulse generation beyond 100 gbit s and its relation to ofdm
    Optics Express, 2012
    Co-Authors: Rene Schmogrow, Benedikt Baeuerle, David Hillerkuss, B. Nebendahl, M Winter, Matthias Meyer, S Wolf, A Ludwig, Shalva Benezra, J Meyer
    Abstract:

    Nyquist sinc-pulse shaping provides spectral efficiencies close to the theoretical limit. In this paper we discuss the analogy to optical orthogonal frequency division multiplexing and compare both techniques with respect to spectral efficiency and peak to average power ratio. We then show that using appropriate algorithms, Nyquist pulse shaped modulation formats can be encoded on a single wavelength at speeds beyond 100 Gbit/s in real-time. Finally we discuss the proper reception of Nyquist pulses.

Rene Schmogrow - One of the best experts on this subject based on the ideXlab platform.

  • single laser 32 5 tbit s Nyquist wdm transmission
    IEEE\ OSA Journal of Optical Communications and Networking, 2012
    Co-Authors: David Hillerkuss, Rene Schmogrow, Matthias Meyer, S Wolf, M Jordan, P Kleinow, N Lindenmann, P C Schindler, Argishti Melikyan, Xin Yang
    Abstract:

    We demonstrate single-laser 32.5 Tbit/s 16QAM Nyquist wavelength division multiplexing transmission over a total length of 227 km of SMF-28 without optical dispersion compensation. A number of 325 optical carriers is derived from a single laser and encoded with dual-polarization 16QAM data using sinc-shaped Nyquist pulses. As we use no guard bands, the carriers have a spacing of 12.5 GHz equal to the symbol rate or Nyquist bandwidth of the data. We achieve a net spectral efficiency of 6.4 bit/s/Hz using a software-defined transmitter, which generates the electric drive signals for the electro-optic modulator in real time.

  • Nyquist frequency division multiplexing for optical communications
    Conference on Lasers and Electro-Optics 2012, 2012
    Co-Authors: Rene Schmogrow, Stefan Wolf, Benedikt Baeuerle, David Hillerkuss, B. Nebendahl, Christian Koos, Wolfgang Freude, Juerg Leuthold
    Abstract:

    We demonstrate a novel Nyquist FDM scheme where electrical Nyquist pulses on different subcarrier frequencies are transmitted optically. High spectral efficiency, asynchronous operation, and dynamic bandwidth allocation are supported.

  • single laser 32 5 tbit s Nyquist wdm transmission
    arXiv: Networking and Internet Architecture, 2012
    Co-Authors: David Hillerkuss, Rene Schmogrow, Matthias Meyer, S Wolf, M Jordan, P Kleinow, N Lindenmann, P C Schindler, Argishti Melikyan, Xin Yang
    Abstract:

    We demonstrate 32.5 Tbit/s 16QAM Nyquist WDM transmission over a total length of 227 km of SMF-28 without optical dispersion compensation. A number of 325 optical carriers are derived from a single laser and encoded with dual-polarization 16QAM data using sinc-shaped Nyquist pulses. As we use no guard bands, the carriers have a spacing of 12.5 GHz equal to the Nyquist bandwidth of the data. We achieve a high net spectral efficiency of 6.4 bit/s/Hz using a software-defined transmitter which generates the electrical modulator drive signals in real-time.

  • real time Nyquist pulse generation beyond 100 gbit s and its relation to ofdm
    Optics Express, 2012
    Co-Authors: Rene Schmogrow, Benedikt Baeuerle, David Hillerkuss, B. Nebendahl, M Winter, Matthias Meyer, S Wolf, A Ludwig, Shalva Benezra, J Meyer
    Abstract:

    Nyquist sinc-pulse shaping provides spectral efficiencies close to the theoretical limit. In this paper we discuss the analogy to optical orthogonal frequency division multiplexing and compare both techniques with respect to spectral efficiency and peak to average power ratio. We then show that using appropriate algorithms, Nyquist pulse shaped modulation formats can be encoded on a single wavelength at speeds beyond 100 Gbit/s in real-time. Finally we discuss the proper reception of Nyquist pulses.

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