https://www.theregister.co.uk/2017/09/28/boffins_sling_around_entangled_photons_at_telco_wavelengths/ >One of the hurdles facing photon-based quantum systems using entangled photons is that it's hard to create them at the 1550 nm wavelengths used in telecommunications systems. >Entanglements are the basis for all sorts of hot-boffin stuff: quantum information processing, repeaters, photon-based key exchange, and fully quantum communication systems.