Using Air to Amplify Light (IMAGE) Ecole Polytechnique Fédérale de Lausanne Caption New hollow-core optical fibers that are filled with either air or gas. Credit Alain Herzog/2020 EPFL Usage Restrictions None License Licensed 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.