There's supposedly a 255Tbps multi-mode cable[0] as well.
[0]: http://www.extremetech.com/extreme/192929-255tbps-worlds-fas...
[0]: http://www.extremetech.com/extreme/192929-255tbps-worlds-fas...
A singlemode fiber is limited to about 100 Tbps per fiber at 10 bits/s/Hz. It is not obvious to me how much bandwidth usage has to grow until it becomes more economical to deploy this new kind of fiber rather than multiple (existing) singlemode fibers. For example, for high bandwidth applications MPO connectors with 12 or 24 fibers per connectors are used.
The Nyquist rate is modulation dependent. Optical fiber can certainly achieve spectral efficiency over 2 bits/s/Hz.