> Research into OAM has suggested that light waves could carry hitherto unprecedented quantities of data through optical fibres. According to preliminary tests, data streams travelling along a beam of light split into 8 different circular polarities have demonstrated the capacity to transfer up to 2.5 terabits of data (equivalent to 66 DVDs or 320 gigabytes) per second.[40]
Note that we could already theoretically pack data into separate spatial modes (c.f. [0]), but the problem is in a real fiber, energy will leak from one mode into another, limiting useful signal. Compounding this is that different modes can propagate at different velocities, so you can e.g. have energy leak from mode A to B, travel more slowly for a moment, then back from B to A, which effectively smears your A signal even if you filter on the ends. This is why single mode fiber (i.e. fiber thin enough that only the 00 mode fits) is used for high data rates/long distances. The same thing can happen with polarization modes. So there are real engineering challenges to actually make it be useful rather than harmful (this is all recollection of uni courses 15 years ago, but it seems single mode fiber has only become more popular, so I suppose it's still an issue).
I swear these random Wikipedia articles posted on HN now and then are like aliens nudging us towards higher technology :)
I have never been able to understand light and I probably never will. Electromagnetism in general. Like actually wrap by head around and grok it intuitively
> [40] https://www.bbc.co.uk/news/science-environment-18551284
Fun!
[0] https://en.wikipedia.org/wiki/File:Intensity_profiles_of_Lag...
I have never been able to understand light and I probably never will. Electromagnetism in general. Like actually wrap by head around and grok it intuitively
Spin angular momentum of light (SAM). https://en.wikipedia.org/wiki/Spin_angular_momentum_of_light
Angular momentum of light (with nice video) https://en.wikipedia.org/wiki/Angular_momentum_of_light