Tuned Resonators Allow Control of Electromagnetically Induced Transparency

Researchers at Washington University in St. Louis have devised an optical resonator system that can be used to turn transparency on and off. The ability to manipulate electromagnetically induced transparency (EIT) without the introduction of an outside influence, such as additional photons, could provide scientists and engineers with more precise control over how much light passes through a medium. The team used whispering gallery mode resonators (WGMRs) for its system. Two WGMRs were indirectly coupled by a fiber optic line. The first resonator was higher in quality, exhibiting just one imperfection. Researcher Changqing Wang added a tiny pointed material to the high-quality resonator that acted like a nanoparticle. By moving this...