Increasing the capacity of fiber-optic cables might one day be possible through the exploitation of a part of the signal commonly thought of as substandard. That imperfect element in a carrier, called \u201cnoise\u201d is usually something one tries to avoid\u2014it can muddy the accurate reading of the data.\nHowever, scientists now suggest that one could, in fact, embrace the rubbishy, and thus far unusable, part of the signal to hold data and allow it to be decoded. The ordinarily data-obscuring hubbub could potentially be harnessed and used to increase data capacity in light waves.\n\u201cInformation is encoded in the correlated noise between spatially separated light waves,\u201d writes Oliver Morsch in an article on the website of ETH Zurich, a technical and scientific university. \u201cThe new coding technology, developed by ETH researchers, makes it possible to make better use of the transmission capacity of optical fibers.\u201d\n\nNoise occurs when signals are sent. It\u2019s a kind of unwanted fluctuation adjacent to the signal. It\u2019s not actually part of the signal, but it\u2019s present in varying degrees nonetheless. In this case, the developers argue that noise should be capitalized on and considered just another multiplex. Multiplexing is where more signals are cleverly sent than the number of transmission channels available. In other words, they say one should look at noise simply as a channel\u2014just like frequencies in a radio broadcast. All you have to do, then, is figure out how to encode and decode data in that noise. The key to it is figuring interference.\nShawn Divitt, an American Ph.D. student, came up with the school\u2019s direction in the work. He used a traditional double-split experiment concept. That\u2019s where splitting waves creates phase shifts, revealing an interference pattern (Wikipdia). Divitt experimented with identifying the extent that predictions can be made about those phase shifts, based on the correlations between the light waves in the two splits.\n\u201cCorrelations indicate how well one can predict, for instance, the oscillatory phase of one light wave if one knows the phase of the other wave,\u201d Morsch writes. \u201cEven if both phases are \u2018noisy,\u2019 meaning their values fluctuate, they can still do so in a more or less synchronized fashion.\u201d\nThe academics exploited the fact that strong correlations create visibly apparent interference and that weak ones cause the patterns to wash out. \u201cThe idea was to generalize that principle and to use it to encode information,\u201d Divitt says in the ETH Zurich article.\nSecurity and cost benefits\nInterestingly, security ended up being a bi-product. The researchers explain that not only do they potentially increase the capacity of fiber through the use of the noise channels building on the data-encoded interference patterns, but that intrusions, where if someone tried to record the interference pattern, would be highly obvious. The subterfuge would obviously grab too much diverted optical power attempting it, and the hacker would be fingered.\nCost is also an advantage, they say. The channel doesn\u2019t actually require extra resources, like light, to be produced, unlike a traditional capacity-increasing methods. \u201cTheir method does not require coherent laser light. It should be cheaper than conventional technologies,\u201d Morsch says.