Weakly-coupled mode division multiplexing(MDM)technique is considered a promising candidate to enhance the capacity of an optical transmission system,in which mode multiplexers/demultiplexers(MMUX/MDEMUX)with low inse...Weakly-coupled mode division multiplexing(MDM)technique is considered a promising candidate to enhance the capacity of an optical transmission system,in which mode multiplexers/demultiplexers(MMUX/MDEMUX)with low insertion loss and modal crosstalk are the key components.In this paper,a low-modal-crosstalk 4-mode MMUX/MDEMUX for the weakly-coupled triple-ring-core few-mode fiber(TRC-FMF)is designed and fabricated with side-polishing processing.The measurement results show that a pair of MMUX/MDEMUX and 25 km weakly-coupled TRC-FMF MDM link achieve low modal crosstalk of lower than−17.5 dB and insertion loss of lower than 11.56 dB for all the four modes.Based on the TRC-FMF and all-fiber MMUX/MDEMUX,an experiment for 25 km real-time 4-mode 3-λwavelength division multiplexing(WDM)-MDM transmission is conducted using commercial 400G optical transport network(OTN)transceivers.The experimental results prove weakly-coupled MDM techniques facilitate a smooth upgrade of the optical transmission system.展开更多
We propose and experimentally demonstrate a novel scheme to realize polarization-division-multiplexing quadrature-phase-shift-keying (PDM-QPSK) signal transmission over fiber, wireless and fiber at Wband (75-110 GH...We propose and experimentally demonstrate a novel scheme to realize polarization-division-multiplexing quadrature-phase-shift-keying (PDM-QPSK) signal transmission over fiber, wireless and fiber at Wband (75-110 GHz). The generation of polarization multiplexing millimeter-wave (mm-wave) wireless signal is based on the photonic technique. After 20-km fiber transmission, polarization diversity and heterodyne beating are implemented to convert the polarization components of the polarization-multiplexing signals from the optical baseband to W-band so that up to 16 Gb/s mm-wave signals can be delivered over 2-m 2~2 multiple-input multiple-output (MIMO) wireless link. At the receiver base station (BS), polarization combination reconstructs the PDM-QPSK signal which is then launched into another 20-km fiber. In the experiment, coherent detection is introduced to improve receiver sensitivity and constant modulus algorithm (CMA) is applied for polarization de-multiplexing. The bit-error-ratio (BER) for 16-Gb/s PDM- QPSK signal delivery is below the forward-error-correction (FEC) threshold of 3.8× 10-3 with the optical signal-to-noise ratio (OSNR) above 11.8 dB.展开更多
We experimentally demonstrate an 80-channel wavelength division multiplexing(WDM)transmission system over a 400 km fiber link.Raman amplification results in a non-flat WDM signal spectrum.Therefore,bit allocation opti...We experimentally demonstrate an 80-channel wavelength division multiplexing(WDM)transmission system over a 400 km fiber link.Raman amplification results in a non-flat WDM signal spectrum.Therefore,bit allocation optimization is used to enable different channels to carry different order quadrature amplitude modulation signals according to their optical signal-noise-ratios.A neural network equalizer based on a convolutional neural network(CNN),long shortterm memory(LSTM)network,and fully connected(FC)layer structure is adopted in Rx digital signal processing,in which CNN is used for characteristic extraction,LSTM is used for equalization and demodulation,and FC layers are used for output.After transmission,the bit error rate of all channels is below the 25%soft-decision forward error correction threshold,and the line rate reaches 53.76 Tbit/s.展开更多
基金supported in part by the ZTE Industry-University-Institute Cooperation Funds.
文摘Weakly-coupled mode division multiplexing(MDM)technique is considered a promising candidate to enhance the capacity of an optical transmission system,in which mode multiplexers/demultiplexers(MMUX/MDEMUX)with low insertion loss and modal crosstalk are the key components.In this paper,a low-modal-crosstalk 4-mode MMUX/MDEMUX for the weakly-coupled triple-ring-core few-mode fiber(TRC-FMF)is designed and fabricated with side-polishing processing.The measurement results show that a pair of MMUX/MDEMUX and 25 km weakly-coupled TRC-FMF MDM link achieve low modal crosstalk of lower than−17.5 dB and insertion loss of lower than 11.56 dB for all the four modes.Based on the TRC-FMF and all-fiber MMUX/MDEMUX,an experiment for 25 km real-time 4-mode 3-λwavelength division multiplexing(WDM)-MDM transmission is conducted using commercial 400G optical transport network(OTN)transceivers.The experimental results prove weakly-coupled MDM techniques facilitate a smooth upgrade of the optical transmission system.
基金supported by the National Natural Science Foundation of China(Nos.61177071and 61250018)the National"863"Program of China(Nos.2011AA010302 and 2012AA011302)+1 种基金the National Key Technology R&D Program of China(No.2012BAH18B00)the International Cooperation Program of Shanghai Science and Technology Association(No.12510705600)
文摘We propose and experimentally demonstrate a novel scheme to realize polarization-division-multiplexing quadrature-phase-shift-keying (PDM-QPSK) signal transmission over fiber, wireless and fiber at Wband (75-110 GHz). The generation of polarization multiplexing millimeter-wave (mm-wave) wireless signal is based on the photonic technique. After 20-km fiber transmission, polarization diversity and heterodyne beating are implemented to convert the polarization components of the polarization-multiplexing signals from the optical baseband to W-band so that up to 16 Gb/s mm-wave signals can be delivered over 2-m 2~2 multiple-input multiple-output (MIMO) wireless link. At the receiver base station (BS), polarization combination reconstructs the PDM-QPSK signal which is then launched into another 20-km fiber. In the experiment, coherent detection is introduced to improve receiver sensitivity and constant modulus algorithm (CMA) is applied for polarization de-multiplexing. The bit-error-ratio (BER) for 16-Gb/s PDM- QPSK signal delivery is below the forward-error-correction (FEC) threshold of 3.8× 10-3 with the optical signal-to-noise ratio (OSNR) above 11.8 dB.
文摘We experimentally demonstrate an 80-channel wavelength division multiplexing(WDM)transmission system over a 400 km fiber link.Raman amplification results in a non-flat WDM signal spectrum.Therefore,bit allocation optimization is used to enable different channels to carry different order quadrature amplitude modulation signals according to their optical signal-noise-ratios.A neural network equalizer based on a convolutional neural network(CNN),long shortterm memory(LSTM)network,and fully connected(FC)layer structure is adopted in Rx digital signal processing,in which CNN is used for characteristic extraction,LSTM is used for equalization and demodulation,and FC layers are used for output.After transmission,the bit error rate of all channels is below the 25%soft-decision forward error correction threshold,and the line rate reaches 53.76 Tbit/s.