Subsea Cables & Internet Infrastructure

Amazon's North American fibre optic network below. Its global network consists of nine million kilometers of owned fibre pairs. Amazon spent the last year experimenting with hollow core fibre and is now ready to join Microsoft in long haul deployments. See their blog for more setails:  https://aws.amazon.com/blogs/aws-insights/building-resilience-inside-awss-nine-million-kilometers-of-fiber-optic-cabling/. Microsoft has deployed hollow core fibre in the long haul to connect three AI data centres. It owns the leading hollow core manufacturer and research company, Lumenisity.  New hollow core designs unveiled in a recent Nature Photonics paper have solved the main obstacle to long haul deployment, namely high attenuation. High attenuation simply means light pulses fade rapidly and hence require frequent amplification. In contrast, Luminisity's new hollow core design unveiled in the Nature publication has 50% less attenuation than standard fibre. This means it can be incorpor...

Hollow core enjoys 33% lower latency than standard solid core single mode fibre. Moreover, it offers at least 50% more bandwidth because a much wider spectrum band can be used. In contrast, solid glass is hobbled by high attenuation outside the C and L bands. A final advantage is hollow core exhibits little chromatic dispersion. Single mode fibre is bedeviled by polar mode and chromatic dispersion. In each case, the speed of light through glass varies sufficiently by wavelength to blur the signal by the time it reaches the far end. The coherent optics revolution was largely about using digital signal processing to unscramble the signal or more precisely to use physics to work backwards and infer the original, pristine signal. But hollow core technology until now has been stymied by very high optical attenuation. This simply means the light fades rapidly as it passes through the hollow core. The light is absorbed rapidly by the surrounding glass border due to the absence of refraction. ...

The era of subsea fibre optic technology began with a very simple, elegant approach. In the digital world we rely on binary code as the language for networks, computer processing, and storage. One advantage of the binary format is that any data can be represented by only two symbols, zero and one. This means faster and cheaper processing since there are only two fundamental building blocks to which technology must develop physical counterparts. Binary makes this particularly easy. The absence of  an electric charge, magnetic orientation or pulse of light is interpreted as a zero. Their presence is interpreted as a one. This simple schema leads to relatively infrequent errors or mistakes. And just as importantly, errors are easily detected and fixed. In contrast, an analog system relies on a continuous range of values and hence can have many fundamental building blocks. While this might seem more efficient due to the infinite richness of potential values rather than relying on longe...