Graphene Chip Filter Unwanted Light (IMAGE) Ecole Polytechnique Fédérale de Lausanne Caption Three layers of graphene are used to filter out unwanted electromagnetic radiation in the Terahertz frequency range. Credit Alain Herzog / EPFL Usage Restrictions Related to EPFL research. 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.