Xiang Zhang SHG Research Group (IMAGE) DOE/Lawrence Berkeley National Laboratory Caption (From left) Yu Ye, Xiaobo Yin, Xiang Zhang and Ziliang Ye used second-harmonic generation imaging to discover strong nonlinear optical resonance along the edges of single layers of molybdenum disulfide. Credit Photo by Roy Kaltschmidt, 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.