Single channel transmission

  • Jeppesen, Palle (Project Manager)
  • Pedersen, Rune Johan Skullerud (Project Participant)
  • Rasmussen, Christian Jørgen (Project Participant)
  • Elnegaard, Nils Kristian (Project Participant)
  • He, Yongqi (Project Participant)
  • Jørgensen, Bo Foged (Project Participant)
  • Zhang, Xiupu (Project Participant)
  • Nissov, Morten (Project Participant)

    Project Details


    A main research subject here has been 10 Gbit/s transmission on standard optical fibers. Theoretical and experimental investigations of unrepeatered transmission using pre-chirp and pre-distortion as well as post compensation in order to balance SPM (Self Phase Modulation) and dispersion have been carried out. The main experimental milestone was to transmit 250 km on standard fiber without any amplification in the transmission path. This was achieved by pre-distortion of the 10 Gbit/s signal as well as post-compensation of the dispersion. Using two in-line amplifiers a transmission span of 300 km standard fiber was demonstrated without any regeneration. Comparable computer simulations have been performed illustrating the importance of using negative prechirp and finite extinction ratio. The use of optical phase conjugation is another technique to overcome limitations of dispersion. This technique has been investigated in detail theoretically. Different ways to produce the phase conjugated signal have been investigated theoretically as well as experimentally.
    CBT 4 also participated in the Danish 10 Gbit/s field trial performed together with Tele Denmark and DSC Communications. The main contributions have been a clock recovery circuit and participation in the development of a system simulator as well as system simulations using the developed simulator. The latter has lead to a number of contributions to the ITU standardisation body.
    A semi-analytical erbium-doped fiber amplifier model has been extended to the self-saturation regime so that high gain amplifiers can be investigated without the need for solving the rate equations numerically.
    Publications: LD 120, LD-123, P-1313, P-1335, P 1336, P 1337, P 1385, P 1457 and P 1458
    Effective start/end date01/01/199631/12/1997