Gouy phase anomaly (IMAGE) Tampere University Caption Conceptual render displaying the difference between a structured laser beam (magenta) and a two-photon quantum state of light being focused on a single mode fibre. Photo: Markus Hiekkamäki / Tampere University. Credit Markus Hiekkamäki, Tampere University Usage Restrictions Image may be used in relation to this article. 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.