WGM microresonators (IMAGE) Washington University in St. Louis Caption Researchers created two WGM microresonators with different absorption losses and coupled their optical fields by setting them close together. Each resonator is coupled to a fiber waveguide. By changing the gap between the resonators and waveguides, they were able to tune the coupling loss. Credit Washington University in St. Louis/Lan Yang Usage Restrictions Use allowed with proper attribution License Original 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.