Arbitrary waveform can be synthesized by two orthogonal components: in-phase and quadrature components. Thus, if we can manipulate the two components independently, various complicated modulation can be achieved. This...Arbitrary waveform can be synthesized by two orthogonal components: in-phase and quadrature components. Thus, if we can manipulate the two components independently, various complicated modulation can be achieved. This technique is called vector modulation, which is commonly used in wireless radio communication systems where the carrier frequency is lower than 100GHz. On the other hand, in lightwave transmission systems, the carrier frequency is higher than 100THz, and the stability of the signal sources would be much poorer than in radio systems, so that the simplest modulation format (on-off-keying) was often used in commercial systems. However, recently, various modulation techniques such as quadrature amplitude modulation, etc., have been demonstrated by using precise and rapid lightwave control. In this report, we review recent progress in optical vector modulation technologies which can generate highspeed and complicated optical signals. Integrated optical modulators can synthesize multi-level signals in photonic circuits.展开更多
The principle of a novel orthogonal modulation format of differential 8-1evel phase-shift keying amplitude-shift keying （D8PSK/ASK） with differential bi-phase encoding （DBC） is introduced. Based on it, an optical ...The principle of a novel orthogonal modulation format of differential 8-1evel phase-shift keying amplitude-shift keying （D8PSK/ASK） with differential bi-phase encoding （DBC） is introduced. Based on it, an optical labeling scheme, in which the payload is 100 Gbit/s D8PSK signal and the label is 10 Gbit/s DBC-ASK signal, is proposed and simulated. The results arc compared with other current schemes, and the effects of transmission range, modulation extinction ratio （ER） and received power on system performance are analyzed, respectively. The results show that the spectrum efficiency and bit error rate （BER） are improved greatly, and when the modulation ER is increased to 11 dB, the balanced performance between the payload and label is achieved.展开更多
A tunable modulation format converter based on spectral line-by-line pulse shaper is proposed to realize different format conversions.The pulse shaper works as a format converter by setting its frequency response equi...A tunable modulation format converter based on spectral line-by-line pulse shaper is proposed to realize different format conversions.The pulse shaper works as a format converter by setting its frequency response equivalent to the transform function between two formats.The working principles show that the format converter is suitable for different formats by adjusting its frequency response.Examples of format conversion from return to zero differential phase-shift keying(RZ-DPSK) to on-off keying(OOK) with different data packets and from return to zero(RZ) to non-return to zero(NRZ) are given.The results show that the format converter is not only suitable for different formats but also for random data packets.展开更多
文摘Arbitrary waveform can be synthesized by two orthogonal components: in-phase and quadrature components. Thus, if we can manipulate the two components independently, various complicated modulation can be achieved. This technique is called vector modulation, which is commonly used in wireless radio communication systems where the carrier frequency is lower than 100GHz. On the other hand, in lightwave transmission systems, the carrier frequency is higher than 100THz, and the stability of the signal sources would be much poorer than in radio systems, so that the simplest modulation format (on-off-keying) was often used in commercial systems. However, recently, various modulation techniques such as quadrature amplitude modulation, etc., have been demonstrated by using precise and rapid lightwave control. In this report, we review recent progress in optical vector modulation technologies which can generate highspeed and complicated optical signals. Integrated optical modulators can synthesize multi-level signals in photonic circuits.
基金supported by the National Basic Research Program of China (No.2010CB328300)the National Natural Science Foundation of China (Nos.61077050, 61077014 and 60932004)+2 种基金the Foundation of State Key Laboratory of Optical Communication Technologies and Networks (WRI) (No.2010OCTN-02)the Fundamental Research Funds for the Central Universities (Nos.2011RC0307 and 2009 RC0314)the Natural Science Foundation of Hebei Province (No.F2010001045)
文摘The principle of a novel orthogonal modulation format of differential 8-1evel phase-shift keying amplitude-shift keying （D8PSK/ASK） with differential bi-phase encoding （DBC） is introduced. Based on it, an optical labeling scheme, in which the payload is 100 Gbit/s D8PSK signal and the label is 10 Gbit/s DBC-ASK signal, is proposed and simulated. The results arc compared with other current schemes, and the effects of transmission range, modulation extinction ratio （ER） and received power on system performance are analyzed, respectively. The results show that the spectrum efficiency and bit error rate （BER） are improved greatly, and when the modulation ER is increased to 11 dB, the balanced performance between the payload and label is achieved.
基金supported by the National Natural Science Foundation of China(No.61377075)New Century Excellent Talents in University(No.NCET-07-0611)
文摘A tunable modulation format converter based on spectral line-by-line pulse shaper is proposed to realize different format conversions.The pulse shaper works as a format converter by setting its frequency response equivalent to the transform function between two formats.The working principles show that the format converter is suitable for different formats by adjusting its frequency response.Examples of format conversion from return to zero differential phase-shift keying(RZ-DPSK) to on-off keying(OOK) with different data packets and from return to zero(RZ) to non-return to zero(NRZ) are given.The results show that the format converter is not only suitable for different formats but also for random data packets.
