Hotter than infinity - Light pulses can behave like an exotic gas

PhD candidate Monika Monika at the set-up where the experiments were conducted. Image: Ira Winkler/Universität Jena - Ulf Peschel and his team report in the magazine "Science" that the propagation of optical pulses through an optical fibre follows the rules of thermodynamics. In our modern society huge amounts of data are transmitted every day, mainly as short optical pulses propagating through glass fibres. With the steadily increasing density of such optical signals, their interaction grows, which can lead to data loss. Physicists at the Friedrich Schiller University Jena and the College of Optics and Photonics in Orlando, Florida are investigating how to control large numbers of optical pulses as precisely as possible to reduce the effect of such interactions. To this end they have monitored an ensemble of optical pulses as they propagated through an optical fibre and have found that itfollows fixed rules - albeit mainly those of thermodynamics. In the issue of the renowned journal "Science" published today (10.3.23), the team led by Ulf Peschel reports on measurements on a sequence of pulses that travel thousands of kilometres through glass fibres that are only a few microns thin.