Coherent Optical Transport

Coherent Terabit Communication (CoT) is the key technology for ultra-high speed data transmission in core networks, metro networks and inter-data center communication.


In recent years and decades the speed in which we generate, consume and process information has been growing faster than the increase in information transport capacity. While the transport capacity increases by about 20% per year, the increase in information generation and processing is around 60%. It is expected, that this mismatch will further increase in the next years, driven by the implementation of the next generation of mobile services (5G).

Optical fiber communication networks provide the required capacity and reliability for today's high-bandwidth internet applications and services and form the backbone of all wired or wireless services. Coherent optical techniques allow to modulate amplitude, phase and polarization of the light for data transport resulting in unprecedented per-channel data rates spectral efficiency, flexibility and robustness. While coherent optical transport is a widespread technique for longhaul terrestrial and transoceanic transmission, it currently also migrates to data center interconnect, access and short reach scenarios.

The current challenge in coherent optical transmission is to increase the transported data capacity per wavelength channel to 1 Tbit/s. But at the same time, the cost, power consumption and footprint per transported bit needs to decrease. In particular for applications in data center interconnects or metro and access networks.

Coherent optical transmission can be combined with other techniques for transport capacity and efficiency increase, such as Multiband Transmission, Multi-mode / Multi-core Transmission, Advanced Modulation Formats, Optical Time Divison Multiplexing, OFDM / Nyquist WDM or Software Defined Networks.

    Related Projects

    • OptiCON
    • SPEED