Absorption and dispersion in the atomic medium of a ladder system with electromagnetically induced lower-level interference are examined. The absorption-dispersion relation is discussed. It is found that even if the probe field is in resonance with the corresponding atomic transition, the refraction index can still be made large with a vanishing absorption.
机构:
Center for Optics & Optoelectronics Research, College of Science, Zhejiang University of TechnologyInstitute of Optics, Department of Physics, Zhejiang University