ELECTROMAGNETICALLY-INDUCED FOCUSING

The theoretical basis for electromagnetically-induced focusing (EIF), which is caused by spatial variations-in the coupling laser strength i n an electromagnetically-induced transparency (EIT) experiment, is stu died in detail. Using a numerical model it is shown that radial change s in both absorption and refractive index are important in predicting the probe beam's propagation conditions. Detailed calculations of the focusing and defocusing during EIF under various conditions are presen ted and compared with appropriate experiments. Diffraction like patter ns are predicted for, and observed on, a probe beam after propagation through a smaller EIT aperture.