Coupled electron-photon pairs (IMAGE) Max-Planck-Gesellschaft Caption An illustration of the generation of coupled electron-photon pairs. A beam of free electrons (yellow) passes through a ring-shaped resonator (black), producing single photons. This creates a coupled electron-photon pair with closely linked properties in energy content and temporal occurrence. Credit Ryan Allen / Second Bay Studios Usage Restrictions Use of images is limited to editorial coverage of scientific topics relating to the activities of the Max Planck Society. Any kind of commercial use (including, in particular, the exploitation of images by means of sale or incorporation in image databases or image catalogues) as well as any promotional use/use for merchandise purposes, disclosure to third parties or granting of related rights to third parties is expressly not permitted. License Original content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.