Focused Electromagnetic Fields (IMAGE) University of Innsbruck Caption The more waveguide modes are excited, the more focused the electromagnetic fields become. Credit IQOQI Innsbruck Usage Restrictions The picture may be used for editorial purposes only. It is protected by copyright. The use is free of charge if the reference is mentioned. 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.