The Experts below are selected from a list of 25365 Experts worldwide ranked by ideXlab platform
Masataka Nakazawa - One of the best experts on this subject based on the ideXlab platform.
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10 tbit s qam quantum noise stream cipher Coherent Transmission over 160 km
Journal of Lightwave Technology, 2020Co-Authors: Masato Yoshida, Toshihiko Hirooka, Keisuke Kasai, Takashi Kan, Masataka NakazawaAbstract:We describe in detail our recent demonstration of a 10 Tbit/s secure physical layer Transmission that we achieved by using digital Coherent QAM quantum noise stream cipher (QNSC) and injection-locked WDM techniques. We used an FPGA-based transmitter and receiver to demonstrate a 165 channel polarization-multiplexed WDM 5 Gbaud 128 QAM/QNSC (70 Gbit/s) on-line Transmission over 160 km with a spectral efficiency of 6 bit/s/Hz. In the present system, the original 128 QAM data were encrypted in a 1024 x 1024 QAM format using basis information. The encrypted signal was then masked by a large ASE noise, which reduced the detection "success" probability for an eavesdropper to 0.13 % for each symbol. As a result, the total number of brute-force attacks needed to obtain the entire basis information was as high as . Furthermore, the multiplicity of the original QAM data and the seed keys used to generate the basis information were randomly changed with time, which enabled us to greatly increase the security performance of the QAM/QNSC system.
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10 tbit s qam quantum noise stream cipher Coherent Transmission over 160 km
Optical Fiber Communication Conference, 2020Co-Authors: Masato Yoshida, Toshihiko Hirooka, Keisuke Kasai, Takashi Kan, Masataka NakazawaAbstract:We present the first 10 Tbit/s secure physical layer Transmission over 160 km with a spectral efficiency of 6 bit/s/Hz by using digital Coherent QAM quantum noise stream cipher (QNSC) and injection-locked WDM techniques.
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experimental and theoretical analyses of gawbs phase noise in multi core fiber for digital Coherent Transmission
Optical Fiber Communication Conference, 2020Co-Authors: Naoya Takefushi, Toshihiko Hirooka, Keisuke Kasai, Masato Yoshida, Masataka NakazawaAbstract:We present the phase noise caused by guided acoustic-wave Brillouin scattering (GAWBS) in a 125-µm four-core-fiber. Phase noise induced by higher-order TR n , m modes was found to be dominant rather than that of the R 0,m mode.
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backward rayleigh scattering suppressed 160 gbit s 256 qam injection locked bidirectional Coherent Transmission for next generation mobile fronthaul
European Conference on Optical Communication, 2018Co-Authors: Keisuke Kasai, Toshihiko Hirooka, Masato Yoshida, Katsumi Lwatsuki, Masataka NakazawaAbstract:We demonstrate injection-locked bidirectional digital Coherent Transmission for high-capacity next-generation mobile fronthaul. Both up- and down-link 160 Gbit/s, 256 QAM signals are successfully transmitted over 26 km with a loss budget of 23 dB.
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single channel 200 gbit s 10 gsymbol s 1024 qam injection locked Coherent Transmission over 160 km with a pilot assisted adaptive equalizer
Optics Express, 2018Co-Authors: Yixin Wang, Seiji Okamoto, Keisuke Kasai, Masato Yoshida, Masataka NakazawaAbstract:We demonstrate a 10 Gsymbol/s, 1024 quadrature amplitude modulation (QAM) 160 km Coherent Transmission with an injection locking technique. Our newly developed, pilot-assisted adaptive equalizer has greatly improved the precision of waveform distortion compensation, and this has enabled us to increase the symbol rate to 10 Gsymbol/s in a 1024 QAM Transmission. Thus, we could realize a 200 Gbit/s, 1024 QAM Transmission over 160 km with a potential spectral efficiency of 12.6 bit/s/Hz.
Masato Yoshida - One of the best experts on this subject based on the ideXlab platform.
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10 tbit s qam quantum noise stream cipher Coherent Transmission over 160 km
Journal of Lightwave Technology, 2020Co-Authors: Masato Yoshida, Toshihiko Hirooka, Keisuke Kasai, Takashi Kan, Masataka NakazawaAbstract:We describe in detail our recent demonstration of a 10 Tbit/s secure physical layer Transmission that we achieved by using digital Coherent QAM quantum noise stream cipher (QNSC) and injection-locked WDM techniques. We used an FPGA-based transmitter and receiver to demonstrate a 165 channel polarization-multiplexed WDM 5 Gbaud 128 QAM/QNSC (70 Gbit/s) on-line Transmission over 160 km with a spectral efficiency of 6 bit/s/Hz. In the present system, the original 128 QAM data were encrypted in a 1024 x 1024 QAM format using basis information. The encrypted signal was then masked by a large ASE noise, which reduced the detection "success" probability for an eavesdropper to 0.13 % for each symbol. As a result, the total number of brute-force attacks needed to obtain the entire basis information was as high as . Furthermore, the multiplicity of the original QAM data and the seed keys used to generate the basis information were randomly changed with time, which enabled us to greatly increase the security performance of the QAM/QNSC system.
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10 tbit s qam quantum noise stream cipher Coherent Transmission over 160 km
Optical Fiber Communication Conference, 2020Co-Authors: Masato Yoshida, Toshihiko Hirooka, Keisuke Kasai, Takashi Kan, Masataka NakazawaAbstract:We present the first 10 Tbit/s secure physical layer Transmission over 160 km with a spectral efficiency of 6 bit/s/Hz by using digital Coherent QAM quantum noise stream cipher (QNSC) and injection-locked WDM techniques.
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experimental and theoretical analyses of gawbs phase noise in multi core fiber for digital Coherent Transmission
Optical Fiber Communication Conference, 2020Co-Authors: Naoya Takefushi, Toshihiko Hirooka, Keisuke Kasai, Masato Yoshida, Masataka NakazawaAbstract:We present the phase noise caused by guided acoustic-wave Brillouin scattering (GAWBS) in a 125-µm four-core-fiber. Phase noise induced by higher-order TR n , m modes was found to be dominant rather than that of the R 0,m mode.
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backward rayleigh scattering suppressed 160 gbit s 256 qam injection locked bidirectional Coherent Transmission for next generation mobile fronthaul
European Conference on Optical Communication, 2018Co-Authors: Keisuke Kasai, Toshihiko Hirooka, Masato Yoshida, Katsumi Lwatsuki, Masataka NakazawaAbstract:We demonstrate injection-locked bidirectional digital Coherent Transmission for high-capacity next-generation mobile fronthaul. Both up- and down-link 160 Gbit/s, 256 QAM signals are successfully transmitted over 26 km with a loss budget of 23 dB.
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single channel 200 gbit s 10 gsymbol s 1024 qam injection locked Coherent Transmission over 160 km with a pilot assisted adaptive equalizer
Optics Express, 2018Co-Authors: Yixin Wang, Seiji Okamoto, Keisuke Kasai, Masato Yoshida, Masataka NakazawaAbstract:We demonstrate a 10 Gsymbol/s, 1024 quadrature amplitude modulation (QAM) 160 km Coherent Transmission with an injection locking technique. Our newly developed, pilot-assisted adaptive equalizer has greatly improved the precision of waveform distortion compensation, and this has enabled us to increase the symbol rate to 10 Gsymbol/s in a 1024 QAM Transmission. Thus, we could realize a 200 Gbit/s, 1024 QAM Transmission over 160 km with a potential spectral efficiency of 12.6 bit/s/Hz.
Keisuke Kasai - One of the best experts on this subject based on the ideXlab platform.
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10 tbit s qam quantum noise stream cipher Coherent Transmission over 160 km
Journal of Lightwave Technology, 2020Co-Authors: Masato Yoshida, Toshihiko Hirooka, Keisuke Kasai, Takashi Kan, Masataka NakazawaAbstract:We describe in detail our recent demonstration of a 10 Tbit/s secure physical layer Transmission that we achieved by using digital Coherent QAM quantum noise stream cipher (QNSC) and injection-locked WDM techniques. We used an FPGA-based transmitter and receiver to demonstrate a 165 channel polarization-multiplexed WDM 5 Gbaud 128 QAM/QNSC (70 Gbit/s) on-line Transmission over 160 km with a spectral efficiency of 6 bit/s/Hz. In the present system, the original 128 QAM data were encrypted in a 1024 x 1024 QAM format using basis information. The encrypted signal was then masked by a large ASE noise, which reduced the detection "success" probability for an eavesdropper to 0.13 % for each symbol. As a result, the total number of brute-force attacks needed to obtain the entire basis information was as high as . Furthermore, the multiplicity of the original QAM data and the seed keys used to generate the basis information were randomly changed with time, which enabled us to greatly increase the security performance of the QAM/QNSC system.
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10 tbit s qam quantum noise stream cipher Coherent Transmission over 160 km
Optical Fiber Communication Conference, 2020Co-Authors: Masato Yoshida, Toshihiko Hirooka, Keisuke Kasai, Takashi Kan, Masataka NakazawaAbstract:We present the first 10 Tbit/s secure physical layer Transmission over 160 km with a spectral efficiency of 6 bit/s/Hz by using digital Coherent QAM quantum noise stream cipher (QNSC) and injection-locked WDM techniques.
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experimental and theoretical analyses of gawbs phase noise in multi core fiber for digital Coherent Transmission
Optical Fiber Communication Conference, 2020Co-Authors: Naoya Takefushi, Toshihiko Hirooka, Keisuke Kasai, Masato Yoshida, Masataka NakazawaAbstract:We present the phase noise caused by guided acoustic-wave Brillouin scattering (GAWBS) in a 125-µm four-core-fiber. Phase noise induced by higher-order TR n , m modes was found to be dominant rather than that of the R 0,m mode.
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backward rayleigh scattering suppressed 160 gbit s 256 qam injection locked bidirectional Coherent Transmission for next generation mobile fronthaul
European Conference on Optical Communication, 2018Co-Authors: Keisuke Kasai, Toshihiko Hirooka, Masato Yoshida, Katsumi Lwatsuki, Masataka NakazawaAbstract:We demonstrate injection-locked bidirectional digital Coherent Transmission for high-capacity next-generation mobile fronthaul. Both up- and down-link 160 Gbit/s, 256 QAM signals are successfully transmitted over 26 km with a loss budget of 23 dB.
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single channel 200 gbit s 10 gsymbol s 1024 qam injection locked Coherent Transmission over 160 km with a pilot assisted adaptive equalizer
Optics Express, 2018Co-Authors: Yixin Wang, Seiji Okamoto, Keisuke Kasai, Masato Yoshida, Masataka NakazawaAbstract:We demonstrate a 10 Gsymbol/s, 1024 quadrature amplitude modulation (QAM) 160 km Coherent Transmission with an injection locking technique. Our newly developed, pilot-assisted adaptive equalizer has greatly improved the precision of waveform distortion compensation, and this has enabled us to increase the symbol rate to 10 Gsymbol/s in a 1024 QAM Transmission. Thus, we could realize a 200 Gbit/s, 1024 QAM Transmission over 160 km with a potential spectral efficiency of 12.6 bit/s/Hz.
Valter Ferrero - One of the best experts on this subject based on the ideXlab platform.
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narrow linewidth cw laser phase noise characterization methods for Coherent Transmission system applications
Journal of Lightwave Technology, 2008Co-Authors: S Camatel, Valter FerreroAbstract:Several techniques for phase noise PSD measurement of continuous wave (CW) lasers to be used in Coherent Transmission systems are analyzed. Between them, we evaluate two novel techniques. The first employs a homodyne optical phase-locked loop, while the second uses a signal source analyzer. Experimental results obtained by these two methods are compared with classical linewidth measurement methods like self-heterodyne and Michelson interferometer. Limits and accuracy of each method are discussed. Furthermore, the comparison shows that, for Coherent Transmission system applications, only a subset of the analyzed methods is useful for laser phase noise characterization.
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phase noise power spectral density measurement of narrow linewidth cw lasers using an optical phase locked loop
IEEE Photonics Technology Letters, 2006Co-Authors: S Camatel, Valter FerreroAbstract:A novel technique for continuous-wave (CW) laser phase noise power spectral density measurement, useful for Coherent communications, is proposed. It employs a homodyne optical phase-locked loop. Experimental results are compared with a self-heterodyne linewidth measurement and the comparison shows how the proposed measurement method gives more accurate results for Coherent Transmission system applications
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phase noise power spectral density measurement of narrow linewidth cw lasers using an optical phase locked loop
IEEE Photonics Technology Letters, 2006Co-Authors: S Camatel, Valter FerreroAbstract:A novel technique for continuous-wave (CW) laser phase noise power spectral density measurement, useful for Coherent communications, is proposed. It employs a homodyne optical phase-locked loop. Experimental results are compared with a self-heterodyne linewidth measurement and the comparison shows how the proposed measurement method gives more accurate results for Coherent Transmission system applications
Toshihiko Hirooka - One of the best experts on this subject based on the ideXlab platform.
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10 tbit s qam quantum noise stream cipher Coherent Transmission over 160 km
Journal of Lightwave Technology, 2020Co-Authors: Masato Yoshida, Toshihiko Hirooka, Keisuke Kasai, Takashi Kan, Masataka NakazawaAbstract:We describe in detail our recent demonstration of a 10 Tbit/s secure physical layer Transmission that we achieved by using digital Coherent QAM quantum noise stream cipher (QNSC) and injection-locked WDM techniques. We used an FPGA-based transmitter and receiver to demonstrate a 165 channel polarization-multiplexed WDM 5 Gbaud 128 QAM/QNSC (70 Gbit/s) on-line Transmission over 160 km with a spectral efficiency of 6 bit/s/Hz. In the present system, the original 128 QAM data were encrypted in a 1024 x 1024 QAM format using basis information. The encrypted signal was then masked by a large ASE noise, which reduced the detection "success" probability for an eavesdropper to 0.13 % for each symbol. As a result, the total number of brute-force attacks needed to obtain the entire basis information was as high as . Furthermore, the multiplicity of the original QAM data and the seed keys used to generate the basis information were randomly changed with time, which enabled us to greatly increase the security performance of the QAM/QNSC system.
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10 tbit s qam quantum noise stream cipher Coherent Transmission over 160 km
Optical Fiber Communication Conference, 2020Co-Authors: Masato Yoshida, Toshihiko Hirooka, Keisuke Kasai, Takashi Kan, Masataka NakazawaAbstract:We present the first 10 Tbit/s secure physical layer Transmission over 160 km with a spectral efficiency of 6 bit/s/Hz by using digital Coherent QAM quantum noise stream cipher (QNSC) and injection-locked WDM techniques.
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experimental and theoretical analyses of gawbs phase noise in multi core fiber for digital Coherent Transmission
Optical Fiber Communication Conference, 2020Co-Authors: Naoya Takefushi, Toshihiko Hirooka, Keisuke Kasai, Masato Yoshida, Masataka NakazawaAbstract:We present the phase noise caused by guided acoustic-wave Brillouin scattering (GAWBS) in a 125-µm four-core-fiber. Phase noise induced by higher-order TR n , m modes was found to be dominant rather than that of the R 0,m mode.
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backward rayleigh scattering suppressed 160 gbit s 256 qam injection locked bidirectional Coherent Transmission for next generation mobile fronthaul
European Conference on Optical Communication, 2018Co-Authors: Keisuke Kasai, Toshihiko Hirooka, Masato Yoshida, Katsumi Lwatsuki, Masataka NakazawaAbstract:We demonstrate injection-locked bidirectional digital Coherent Transmission for high-capacity next-generation mobile fronthaul. Both up- and down-link 160 Gbit/s, 256 QAM signals are successfully transmitted over 26 km with a loss budget of 23 dB.
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observation of guided acoustic wave brillouin scattering noise and its compensation in digital Coherent optical fiber Transmission
Optics Express, 2018Co-Authors: Masato Yoshida, Masaki Terayama, Seiji Okamoto, Keisuke Kasai, Toshihiko HirookaAbstract:We describe the first observation of guided acoustic-wave Brillouin scattering (GAWBS) phase noise in a digital Coherent optical fiber Transmission. GAWBS noise, which is a forward lightwave generated by thermally excited vibration modes in a cylindrical fiber structure, occurs Coherently not only in a signal at a single carrier frequency, but also in modulated wide-band optical signals. Since the signal-to-GAWBS-noise ratio is independent of signal power, it has caused problems in various fields including quantum optics. We point out that GAWBS noise exists even in a digital Coherent Transmission system such as quadrature amplitude modulation (QAM) and degrades the Transmission performance since the phase noise is inevitably included within the bandwidth of the transmitted data. We propose two analogue and one digital method to compensate for the GAWBS noise and demonstrate improved performance in a QAM digital Coherent Transmission.