Researchers Use Quantum Patterns of Twisted Light to Send Across Single Mode Fiber Optic Cable

(ISPreview.co.uk) A team of South African and Chinese scientists have figure out how to harness multiple quantum patterns of twisted light (from a laser) so that it can be sent across a conventional single mode fibre optic cable (these can usually only support one pattern), which wouldn’t ordinarily be possible without a custom made fibre.
Quantum links are an attractive prospect for future networks because they’re often said to be virtually “un-hackable” as they rely on the use of single particles of light (photons), to transmit data encryption “keys” (QKD – Quantum Key Distribution) across an optical fibre.
The teams from the University of the Witwatersrand (South Africa) and Huazhang University of Science and Technology (China) sought to circumvent current restrictions for single mode fibre. The way they did this was by “entangling the spin-orbit degrees of freedom of a biphoton pair, passing the polarization (spin) photon down the SMF while accessing multiple orbital angular momentum (orbital) subspaces with the other” (i.e. multidimensional entanglement transport).