Microring Laser Cavity Schematic (IMAGE) DOE/Lawrence Berkeley National Laboratory Caption This is a schematic of a PT symmetry microring laser cavity that provides single-mode lasing on demand. Credit Courtesy of Xiang Zhang, Berkeley Lab 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.