Tiny, Tunable Light Source (IMAGE) American Physical Society Caption A novel design for a tunable source of infrared light relies on electrons fired into a tiny hole drilled through a stack of alternating gold and silica layers. Credit Credit: G. Adamo, Optoelectronics Research Centre, University of Southampton 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.