2-D Excitonic Laser (IMAGE) DOE/Lawrence Berkeley National Laboratory Caption In this 2-D excitonic laser, the sandwiching of a monolayer of tungsten disulfide between the two dielectric layers of a microdisk resonator creates the potential for ultralow-threshold lasing. Credit 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.