We demonstrate a single-channel 1.92 Tbit/s, 64 QAM coherent optical pulse optical time-division multiplexing (OTDM) transmission by utilizing frequency-domain equalization (FDE). FDE makes it possible to compensate precisely for the waveform distortions caused by hardware imperfections thus greatly improving the error vector magnitude (EVM) of the demodulated 64 QAM signal compared with that obtained with a conventional FIR filter. As a result, a coherent 64 QAM OTDM transmission over 150 km with a bit error rate of below the forward error correction limit of 2×10-3 (requiring 7% overhead) was achieved for the first time.
ASJC Scopus subject areas
- Atomic and Molecular Physics, and Optics