The Ultimate Guide to Nyquist Subcarriers

Coherent optical transmission has delivered a dramatic enhancement in the capacity-reach product for long-haul and subsea cables. The first wave of coherent systems reached the market around 2011 and delivered a tenfold increase in capacity,with 10 gigabit [10G] wavelengths becoming 100G wavelengths. The first wave of coherent systems located all of the digital processing power in the receiver. Today, a second wave of coherent systems has both transmitter- and receiver-based processing, and can deliver around 30 times the capacity of non-coherent technology.