Whispering-Gallery Raman Microlasers (IMAGE) Washington University in St. Louis Caption The image shows arrays of self-referenced and self-heterodyned Whispering-Gallery Raman microlasers for single nanoparticle detection. A "pump" laser generates a single Raman lasing mode inside the silica resonators. Upon landing of a nanoparticle on the resonator, Raman laser circulating inside the resonator undergo mode splitting leading to two new lasing modes in different colors. Monitoring the changes in the color difference (frequency difference) enables detecting and measuring of nanoparticles with single particle resolution. Credit J. Zhu, B. Peng, S.K. Ozdemir, L. Yang 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.