We demonstrate a single-channel 1.28 Tbit/s-525 km transmission using OTDM of subpicosecond DQPSK signals. In order to cope with transmission impairments due to time-varying higherorder PMD, which is one of the major limiting factors in such a longhaul ultrahigh-speed transmission, we newly developed an ultrafast timedomain optical Fourier transformation technique in a round-trip configuration. By applying this technique to subpicosecond pulses, transmission impairments were greatly reduced, and BER performance below FEC limit was obtained with increased system margin.
- Differential quadrature phase shift keying
- High-speed optical pulse transmission
- Optical Fourier transformation
- Optical phase modulation
- Optical timedivision multiplexing
- Ultrashort optical pulse