U N C O V E R I N G T H E L A Y E R S

the L-band . L-band requires additional amplifiers and the use of lower-volume , more expensive L-band transceivers .

A further cost-effective option is to expand the available spectrum within the existing C-band . Optical technology has evolved over the years , enabling expansion of the C-band from 3.2 THz to 4.8 THz . With the latest generation of optical transceiver and amplification technology , we can cost-effectively extend the C-band further , from 4.8 THz to 6.1 THz , while maintaining uniform performance across the spectrum . This increased range is called the Super C-band .

With 27 % more capacity , network operators can leverage a single set of amplifiers and higher-volume , lower-cost C-band transponders . Additionally , the solution reduces the power consumption per bit of optical line system transmission by as much as 27 % and defers the cost of expanding into the L-band or lighting up new fibre pairs . L-band spectrum can also be expanded in a similar manner as Super C , enabling a total capacity of up to 100 Tb / s on a single fibre pair with Super C + L solutions .

More bands , more fibre types

To support capacity growth further , we will see increased use of transmission outside of the C- and L-bands . It will most likely be the S-band initially , and the combination of S + C + L could almost triple fibre capacity compared to C-band only . To get there , we would need commercial S-band amplifiers based on thulium , rather than erbium , or we could use Raman amplification .

There are also emerging innovations in optical fibre , with hollow-core and multi-core fibres demonstrating viability and improvements in lowering latency , increasing bandwidth and transmission capacity . The manufacturability and operational environment for these fibre technologies will continue to evolve before we see large-scale commercial deployments .

Figure 2 : Fiber spectrum overview

Data centres and their interconnectivity remain critical to our economy . Technology innovations like coherent optical engines , expanded transmission spectrum and new fibre types are required to cost-effectively support growth and improve efficiency . �

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