Bell Labs reported optical transport of electronically multiplexed 107 Gbps data. The researchers said that until now there has been no reported case of a high-speed electronically multiplexed optical signal transmitted at speeds greater than 85.4 Gb/s. Furthermore, no fiber transmission of signals faster than 42.7 Gbps in a spectrally compact non-RZ format have ever been reported.
Bell Labs researchers were able to transmit 10 channels of 107- Gbps traffic, optically modulated using electrical multiplexing, over a distance of 400 kilometers. Key to this breakthrough was the use of an integrated optical equalizer, built as a single-chip photonic integrated circuit.
To achieve the high spectral efficiency of 0.7 bits/s/Hz and total capacity of 1 terabit per second (Tbps) the researchers used nonzero dispersion fiber and a non-return-to-zero (NRZ) format, enabling the researchers to closely space the wavelength channels thus enhancing the efficiency and total capacity.
To address the need to carefully manage signal dispersion at high bit rates, Bell Labs used a dispersion compensating fiber (DCF) that was slope matched to the transmission fiber, reducing the average residual dispersion per span to +21 ps at 1550 nm. The Bell Labs scientists used hybrid EDFA/Raman amplification with counter-propagating Raman pumps to maintain signal quality.
Results were presented in a paper delivered at OFC this week in Anaheim, California.
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