High capacity submarine transmission systems

• Coherent technology unlocked capacity of undersea systems ✓ Increased several times the capacity of the legacy systems ✓ Brought to life new generation of dispersion uncompensated systems with capacities more than 10 Tb/s per fiber • Laboratory experiments are close to Shannon limit • Further increase in capacity can be achieved ✓ Better bandwidth utilization: spectral shaping and variable spectral efficiency ✓ Expansion of the bandwidth into L band • Is SDM the next step? ✓ Power efficiency is an attractive argument